198 199DIETS High-fiber diet How does it work? Stomach STOM Soluble fiber encourages the body to Fiber helps with weight loss in a range use and expel cholesterol, reducing the of ways. It isn’t easily digested, so it risk of developing heart disease. It forms doesn’t provide many calories, but the a gel when mixed with liquid in the bulk makes you feel full quickly. High- stomach. This helps slow the release fiber foods also need a lot of chewing, so of sugar into the bloodstream, avoiding you eat more slowly, meaning your body the sugar rush that is common after eating low-fiber carbohydrates. can register you are full before you overeat. Food is churned Fiber-rich foods also travel slowly through in stomach for the stomach, keeping you full for longer, several hours so it is easier to resist unhealthy snacks. Soluble fiber (see p.24) can even reduce NTESTINE blood sugar spikes after meals, which helps ACHSMALL I to avoid insulin resistance (see pp.216–17). Soluble fiber slows NER sugar absorption in small intestine Large molecule of Gases FOOD IN STOMACH fiber being broken produced by Broccoli provides down by bacterial fermentation vitamins as well as fiber fermentation DIN TINE LARGE INTES LARGE INTESTINE FIVE BEAN CHILI WITH FOLDED WALL OF INTESTINE Bacteria lining wall BULGAR WHEAT AND of intestine BROCCOLI Short-chain fatty acid produced by bacteria Keeping regular BLOODSTREAM Fiber helps keep your gut healthy by Products of fermentation, including bulking out and softening your stool vitamins K and B, enter bloodstream and reducing the time it takes to pass Colon through the bowel. This can help reduce Fiber passes through the stomach and small constipation. Fiber is also prebiotic, intestine relatively unchanged, but in the colon, meaning it feeds beneficial gut bacteria. some types are fermented by bacteria. Although These bacteria produce byproducts that this produces embarrassing gas, it also generates help keep our colon cells healthy and beneficial products including some vitamins and protect against bacteria that can make short-chain fatty acids. Over time, the gut adapts us ill by making the colon more acidic. to a higher-fiber diet and flatulence decreases. The bacteria also produce vitamins B and K, which we can then absorb.
Intermittent fasting Fasting has traditionally been part of many religious SHOULD YOU diets, but recently it has started to gain more interest in EXERCISE ON FAST DAYS? scientific communities. In addition to helping with weight loss, it is thought that intermittent fasting There is evidence to suggest has the potential to produce other health benefits. that exercising while fasting helps the body burn more fat. Common fasting diets However, it makes sense Intermittent fasting diets involve sequenced periods of fasting and non- to limit yourself to moderate fasting. In the 5:2 diet, dieters eat normally on five days a week (feast days) but have a much reduced calorie intake on two nonconsecutive days (fast forms of exercise on days). The alternate day diet involves eating whatever you like one day, then fast days. fasting the next. Diets that involve a restricted feeding window allow you to eat only during a set time period each day—usually of 8–12 hours. DAY 1 DAY 2 DAY 3 DAY 4 DAY 5 5 : 2 DIET FAST FAST ALTERNATE DAY DIET FAST FAST EIGHT-HOUR DIET Fasting menu BREAKFAST LUNCH SUPPER On fasting days, 0 No food calorie intake is Miso Small consumed restricted to about soup turkey 20 one-quarter of the burger recommended daily 18 6 Food eaten in intake. On the right 1 egg 5 asparagus 1 crispbread corn on the cob an eight-hour is an example of a 90 KCAL 60 KCAL 330 KCAL window daily meal schedule of 490 calories. 12
200 201DIET Intermittent fasting Is it good for you? BENEFITS DRAWBACKS The evidence that suggests that Simple rules and easy to follow Possibility of extreme hunger, headaches, and intermittent fasting is good for tiredness on fast days weight loss comes mainly from animal studies (see below). If these No special food or supplements are required Risk of mood swings and irritability results are applicable to humans, these fasting diets could be Possible health benefits Long-term effects not yet understood effective in countering obesity— and the health benefits of that are Offers some flexibility—you don’t need to fast Risk of low blood pressure on fast days may widely known. However, the very few human studies on fasting have on the same days each week make driving dangerous had mixed results and we don’t yet understand the potential negative Some people report increased energy May not suit some people’s lifestyles impacts of fasting. Reduced food costs Can be hard to keep it up over a long period On fast days, frees up time usually spent Some people believe that fasting can lead to planning meals an unhealthy obsession with food DAY 6 DAY 7 Potential health benefits There is growing evidence to support the health benefits of fasting in animals. Positive effects on blood pressure, insulin sensitivity, and the risk of some chronic diseases have led some scientists to believe that fasting has the potential to produce similar health benefits in humans. Increased insulin sensitivity RESULTS OF Higher insulin sensitivity STUDIES ON ANIMALS helps the body to process glucose in carbohydrates more efficiently, reducing Lower blood the risk of obesity and Fighting pressure diabetes. cancers When used both on Fasting has been its own, and alongside shown to reduce blood pressure in mice, and even chemotherapy, fasting has been shown to slow the FAST maintain blood pressure Helps brain growth and spread of Feast and famine levels when they were diseases some cancers Of the variety of fasting regimes available, fed a high-calorie in mice. the three pictured here are among the diet. Fasting has been shown most popular. Fasting involves considerable to slow cognitive decline commitment, and may not suit some in mice with engineered lifestyles, but the degree to which people versions of Alzheimer’s fast varies. Some follow a 500kcal fasting Reduced and Parkinson’s Improved regime (see left), but others commit to cancer risk disease. brain health 300kcal a day, or even nothing but water. Fasting mice have been Increased cell Feeding mice a found to experience resistance restricted-calorie diet significant reductions in has improved brain cell proliferation, The heart and brain neuron regeneration considered an indicator cells in fasting mice have and improved the for cancer risk. cognitive abilities of older mice. become more resistant to the damage caused by heart attack and stroke.
Detoxing CAN NATURAL PRODUCTS EVER DETOX? A recent fad has seen ranges of items, including Although there is very limited drinks, supplements, and even shampoos, being evidence from animal studies sold as “detox” agents that we can use to cleanse that cilantro may help to expel our bodies and eliminate toxins. However, there heavy metals, heavy metal is no scientific evidence to back up such claims. poisoning is a serious The detox claim problem that requires Detox proponents claim that by following a particular diet, or using medical treatment. certain products, we can help our body to flush-out toxins that have built up through our exposure to substances such as alcohol, caffeine, GOJI BERRY tobacco, fat, and sugar. Detoxing can therefore improve our health. Detox methods A whole industry has built up around an array of detox methods and products. These include diet regimes, fasting, food supplements, and even invasive procedures such as colonic irrigation. ACAI BERRY SUPPLEMENTS LAXATIVES FRUIT CELERYHERBAL TEA TOXINS BUILD DETOX ED BEETS-UP GARLIC JUICE SMOOTHIES
202 203DIETS Detoxing What are toxins? Many substances can be harmful in large doses—even water. However, the body has an efficient system in place, featuring the liver and kidneys, which neutralizes or expels excess harmful chemicals daily. Toxins do not accumulate as detox advocates claim. There are a few exceptions, however. Some dangerous chemicals that dissolve in fat can build up in our fat stores over years. Exposure to these should be limited. POPS Iodine Toxic A NORMAL, Persistent An essential metals HEALTHY organic pollutants nutrient, iodine can Fish may contain PERSON HAS can come from paint be toxic in high doses, heavy metals including NO NEED TO and ink, and residues particularly for people mercury. It accumulates DETOX of pesticides with defective in the food chain, so on food. predatory fish may kidneys. have high levels. The reality of detoxing PRODUCT CLAIM REALITY Herbal teas Our bodies have sophisticated Supplements Herbal teas help to flush toxins They can have a diuretic effect, ways of removing most of the Superfoods out of your system making you urinate more—giving unwanted substances we ingest. Detox patches the appearance of “flushing” Therefore, it is doubtful that the Calorie term “detoxing” has any real restriction Supplements boost your body’s While valuable in some cases of validity. The mainstream medical Laxatives detoxing organs with scientifically deficiency, there is no evidence view is that the idea is little more developed vitamin formulas for their detoxing properties than a marketing myth and a waste of time and money. Some foods, such as garlic, help They may contain high amounts to decrease the buildup of of vitamins and minerals that are COLONIC IRRIGATION toxins in the body essential to our general health Colonic irrigation is a potentially Detox patches draw toxins out There is no evidence supporting dangerous practice of inserting through the skin the idea that toxins can be drawn liquids (often herbal concoctions out through the skin or even coffee) through the rectum into the colon, and holding it there Fasting or low-calorie diets will Denying your body the nutrients before expelling it. Despite what help you detox and lose weight it needs to function can result in its advocates claim, the colon does serious health problems not need cleaning, and this practice can perforate its lining, leading Laxatives can help to cleanse Regular use can lead to to serious complications. your colon dependency—you may struggle People have even died from to pass waste without them infections caused by colonic irrigation.
Popular diets With a 2014 WHO report finding 39 percent of adults worldwide overweight or obese, dieting has never been more popular or necessary. But with so many diets available, which are scientifically proven to be healthy and effective? For some, the consensus is clear, but for others, the jury is still out. Lifestyle choices Diet What are its goals? How is it supposed to work? Low-calorie The word “diet” is often used to Low-fat The basic equation for weight loss is to consume fewer calories talk about short-term changes or Very low- than you use—counting calories can help ensure this happens. significant adjustments in eating calorie habits for a set time frame. Low-carb Fat is high in calories, so reducing the amount eaten cuts total Weight loss can often be achieved Low-GI calories consumed and encourages weight loss. In the past, it was in these ways, but the results are (glycemic also thought to help cut cholesterol and heart disease risk. unlikely to stick if a long-term index) change in lifestyle is not made. High-fiber By drastically reducing calorie intake, a very low-calorie diet Indeed, if the dieter simply returns Mediterranean is designed to promote rapid, short-term weight loss. to earlier habits, any weight lost Paleolithic will almost certainly be regained. Intermittent Low-carb diets claim carbohydrates are stored more easily as fat. For sustained weight loss and fasting Some reduce carbohydrates enough that the body starts burning maintenance, healthy choices need Clean eating fat reserves as it enters ketosis, leading to weight loss. to turn into lifelong behaviors. Alkaline Macrobiotic The glycemic index measures how rapidly food raises blood sugar BY 2025 GLOBAL Blood-type levels. Low-GI foods help you feel fuller longer, keeping your body OBESITY LEVELS MAY from producing so much insulin (which promotes fat storage). REACH 18 PERCENT Fiber fills you up and keeps you full for a long time, reducing the IN MEN AND amount you feel you need to eat. Much of it isn’t digested, so it 21 PERCENT doesn’t provide many calories. IN WOMEN Mediterranean people live long and healthy lives. Many have tried DO CRASH imitating their diets in the hope of reaping the same benefits. DIETS WORK? Proponents claim that we haven’t evolved since Paleolithic (Old While following a very low- Stone Age) times, so we can’t process food produced by farming. calorie diet can lead to rapid By replicating our ancestors’ diets, they claim we will be healthier. weight loss, it is essentially impossible to lose more than By restricting calorie intake to particular times of day, or days of the week, this approach is designed to lower the overall calorie about 3lb (1.5kg) of fat in intake and encourage fat burning and weight loss. one week, even if you could eat nothing. Based on a “whole food” approach, clean eating advises avoiding anything “processed” in order to eat a higher quality diet, feel fuller for longer, and be more mindful of the food being consumed. Claims that some foods have an acid-producing effect, and the body has to work hard to bring its pH under control. Eating alkali- producing foods aims to ease this pressure and improve health. This diet focuses on consuming a balance of foods that are locally produced, in keeping with the seasons. Rather than strict guidelines, the food eaten varies from person to person. Advocates of this diet argue that our different blood types affect how we digest food. To optimize health, they say we should eat the right foods for our blood type.
204 205DIETS Popular diets Crash and burn C ABBAGE SOUP A persistently popular fad diet is the cabbage soup diet. Based on eating a low-calorie soup (and little else) for one week, many experts criticize it as a quick fix, with much of the weight lost being water, not fat. This is because reducing calorie intake leads the body to burn through glycogen stores for energy. Glycogen retains water, so using it also releases the “water weight,” but this can be quickly regained. What does it consist of? What do people eat or avoid? Is there evidence that it works? No foods are off limits, but portions are controlled and Yes—reducing your calorie intake is a surefire way to lose weight, but it low-energy-density foods are preferred. can be hard to stick to because you need to track everything you eat. Dieters switch to low-fat versions of products such as cheese and Low-fat products are often high in sugar and may not keep you full. While yogurt, and eat lean cuts of meat. The consumption of high-fat foods, it is a way to cut calories, some fats (such as the unsaturated ones in olive such as oils and spreads, is limited. oil and oily fish) are necessary for health. Some or all meals are replaced with “nutritionally balanced,” Can lead to rapid weight loss at first, but products lack many of the low-calorie, ready-made drinks, soups, or bars. Any other food eaten benefits of normal food. Cannot be followed long-term, and doesn’t should be healthy and low in fat. Products can be very expensive. change eating habits, so weight often returns when the dieting stops. Bread, pasta, grains, and starchy vegetables are off limits. In some Limiting refined carbohydrates is sensible as they are energy-dense and extreme cases, a lot of fruit and vegetables are banned at the start easy to overeat, but cutting out fruit and vegetables is never wise. Can of the diet. Protein and fat are unlimited. help short-term weight loss, but longer-term consequences are not clear. Whole-grain products are promoted, because they have a generally Low-GI isn’t always healthy—fries, for example, are lower-GI than boiled lower GI than their white counterparts. Only carbohydrates have a GI potatoes. But this diet may be beneficial in preventing and treating rating, so fats and protein are not limited. obesity and related diseases, such as type 2 diabetes. Whole-grain cereals, fruit and vegetables (especially with skins) are High-fiber diets can help with weight loss, and have lots of other health good sources of fiber. Processed foods generally aren’t, and fats and benefits, such as reducing the risk of certain cancers, decreasing protein don’t contain fiber. cholesterol levels, and promoting good gut bacteria. Traditional Mediterranean diets focus on fresh vegetables, whole grains, There is some evidence olive oil is protective against a range of olive oil, garlic, and some fish, fruit, and wine. Sugar, red meat, and age-related diseases. The plant-based, high-fiber approach of processed foods are limited. the diet also makes it a good choice. Most grains and dairy are out, but plenty of meat, leafy greens and nuts Eating less processed food and more vegetables is good, but there is no are consumed. Processed food, salt, and sugar are also avoided. evidence that most of us have trouble processing cereals. Our ancestors did not have one specific diet, and we have adapted to more variety. Followers eat normally part of the time and restrict calories dramatically on certain days or at certain times. On fast days, only 500 There is emerging evidence that fasting can benefit health. Many people calories are allowed by some regimes, which is very limiting. lose weight on this diet, as the lack of restriction on non-fast days fits in with a busy lifestyle. There is a focus on expensive “superfoods,” such as chia seeds, goji berries, and organic kale. Normal sugar is out, but honey, maple syrup, Some principles are sound (more fruit and vegetables, fewer refined and coconut sugar are fine, as are foods processed at home. carbohydrates, sugar, and salt) but some advice is illogical—the sugar in honey is just as bad for you as refined sugar. Lemon water is recommended to make your body more alkaline. Fruit and vegetables are encouraged; meat, dairy, and most grains are out. The pH of the blood is tightly controlled. Acidic blood would indicate a serious illness, and drinking lemon water will not help. However, the focus Whole grains, vegetables, and beans are encouraged. Dairy, eggs, meat, on fresh fruit and vegetables in this diet is good. tropical fruits, and nightshade vegetables (including tomatoes and eggplants) are to be avoided. Good for reducing food miles and meat consumption, but devotees miss out on some healthy foods. Its focus on vegetables and whole grains, with Based on ideas of when blood groups evolved and what was eaten by limited fat and sugar, might help you lose weight. ancestors at those times. Type O should eat a “paleo”-style diet high in meat, while A should be vegetarian. B can consume more dairy. There is no evidence that blood type affects the way we process food or that this diet improves health. The theories of when each blood group evolved have been disproven by genetic evidence.
Allergies FIRST EXPOSURE Protein in peanut ingested An allergy is the body’s oversensitive immune response to a substance that should normally be STOMACH harmless. Food allergies cause a variety of symptoms, ranging from the uncomfortable to the life-threatening. TESTINE How allergies work Amino acid IN absorbed In people with food allergies, exposure to specific proteins in into body particular kinds of food causes their body’s immune system to react inappropriately. It triggers the release of chemicals into the 1 Protein absorbed bloodstream that aggravate or inflame different parts of the body. The trigger food—in this case Food allergies may cause skin problems, such as itching and peanuts—is ingested and the proteins in eczema, and digestion issues including nausea and diarrhea. it are broken down into amino acids, which Severe allergies may also cause asthmatic symptoms, or even are absorbed through the gut. Exposure can a systemic reaction—anaphylaxis—that can be fatal. also be through skin contact or inhalation. 1–2 PERCENT OF ADULTS AND IMMUNE 8 PERCENT OF CHILDREN IN CELL THE UK HAVE A FOOD ALLERGY PEANUTS NO SYMPTOMS Antibody released by immune cell 2 Antibodies produced If allergic to peanuts, the body’s immune cells produce antibodies that are specific to the particular allergen. The antibodies travel in the bloodstream. ALLERGIES ON THE RISE Antibody bound to mast cell Food allergies are on the rise in developed countries, but scientists aren’t sure why. One popular idea, known MAST CELL as the “hygiene hypothesis,” suggests that the fact our children don’t encounter as many pathogens, BACTERIA 3 Mast cells such as bacteria, as they used to has somehow The antibodies bind to the surface of affected the natural development of their white blood cells called mast cells, which immune systems. Another theory is that become sensitized. At this stage there are modern lifestyles—including diet, antibiotics, and hygiene—interfere with our gut flora. We know these microbes moderate our immune systems, so this interference may affect how our immune cells are primed, causing allergies. no symptoms of an allergy, but the cells are primed for a second exposure.
SUBSEQUENT EXPOSURE 206 207DIETS How allergies are diagnosed Allergies Skin prick test A combination of a detailed patient history A medic pierces the patient’s skin with and either a skin prick test or blood test tiny amounts of suspected allergens, for food-specific antibodies are used to producing localized allergic responses diagnose food allergies. Food exclusion, in the form of bumps and redness. and blind and placebo-controlled oral food SWOLLEN tests are also effective, but must be done LIPS under careful supervision. T SWOLLEN THROA Treatment options AUTOINJECTOR Emergency treatment The main treatment for allergies is to avoid People with severe allergies may need the trigger food, but this isn’t always easy. to carry with them two autoinjectors (a In severe cases, even tiny amounts of the spring-loaded syringe) of adrenaline for allergen can cause reactions. Medicines are emergency treatment. Adrenaline narrows used to prevent and alleviate the symptoms blood vessels, relieves blood pressure, and reduces swelling. of allergic reactions. For mild allergies, such as hayfever, antihistamines can help by S blocking receptors from binding PEANUTS to histamine chemicals. MAST CELL Protein bound SYMPTOMS OCCUR to antibody 4 Proteins bind to antibodies SWOLLEN HAND On subsequent exposure, mast cells identify the protein allergen, which then binds to the antibodies on the mast cells. This activates a process called degranulation. ONLY IN EXTREME CASES MAST CELL Chemicals such Body-wide allergic as histamine reaction released ABDOMINA Chemicals 6 Anaphylaxis released over In severe cases, known as anaphylaxis, the entire body L PAIN whole body is affected over a very short period, resulting in a combination of extreme 5 Mast cell releases chemicals symptoms that can include As the mast cell degranulates it throat swelling, severe releases histamine and other chemicals into the bloodstream. It is the effect of asthma, and a drop in blood pressure. Emergency these chemicals on the body that treatment is necessary. produces different allergic symptoms.
Intolerances Intolerances occur when the body is unable to digest Lactose intolerance a component of food. They differ from allergies in that This type of intolerance is one of the most they do not aggravate the immune system. People can common. It occurs due to a lack of the be intolerant to a range of foods—and either be born enzyme lactase, which breaks down lactose intolerant, or become sensitive later in life. sugar. Without this enzyme, the sugar is fermented by bacteria in the colon. What causes intolerances? Galactose Glucose Intolerance can occur when you don’t have a particular digestive enzyme that helps break down nutrients. Sometimes, it is a part of the food that can cause intolerances, such as artificial additives, natural chemicals, or toxins. Symptoms often arise hours after eating and may continue for days. They vary from case to case, but commonly include nausea, bloating, cramps, and diarrhea. Rarely, temporary intolerances can arise after bouts of gastroenteritis or courses of antibiotics. Diagnosis Intolerances are difficult to diagnose as symptoms are delayed and more than one intolerance can coexist. Exclusion diets instruct a patient to cut a potentially problematic food out of their diet for a few weeks to see if symptoms improve. If symptoms recur once the food is reintroduced, an intolerance is diagnosed. FOOD Exclusion period Reintroduction period SYMPTOMS TOLERANCE YOGURT Time Live cultures Research has shown that yogurts Creating tolerance with live cultures (bacteria) can help Extended elimination (weeks to months) of the offending relieve the symptoms of lactose food can, in some cases, lead to a rise in tolerance. intolerance, because the bacteria Reintroducing the food in small doses may be tolerated break down the lactose for you. and symptoms may lessen with time. PEOPLE INTOLERANT TO AVOCADOS ARE SENSITIVE TO A SUBSTANCE IN THEM CALLED TYRAMINE
208 209DIETS Intolerances SMALL INTESTINE Lactase enzyme WHAT IS CANDIDA? Lactose sugar Candida is a group of yeasts that live naturally in the body, 1 Lactose in most commonly in the mouth small intestine and vagina. The yeasts may When the cells that line the walls of also live in the gut, as part of the small intestine encounter the the normal gut flora. It is often Lactose digested sugar lactose, they start to produce thought that overgrowth of 2 by lactase the digestive enzyme lactase. Candida in the gut can cause irritable bowel syndrome, but Lactase breaks lactose into research suggests that it may two smaller sugars— be the reverse – bouts of IBS galactose and glucose. can upset the balance in your gut and cause Candida to 3 Galactose and glucose absorbed WHY CAN LACTOSE thrive. This may lead to These two smaller sugars are then INTOLERANCE DEVELOP symptoms akin to having IBS absorbed into the bloodstream by the or even a persistent food small intestine. LATER IN LIFE? intolerance: nausea, gas, diarrhea—leading to Candida 1 Undigested lactose Lactase production decreases being falsely blamed as the Those who are lactose at varying rates with age, so “cause” of these afflictions. intolerant will not have the your ability to digest dairy lactase enzyme, so lactose CANDIDA YEAST cannot be absorbed and instead products may reduce as passes into the large intestine. you get older. Bacteria ferment 2 Bacterial fermentation lactose Lactose is fermented by bacteria living in the large intestine, 3 Disruption in the bowel Acids draw water into the producing gas and acids in the process. bowel, causing diarrhea, while the gas produced by fermentation causes bloating and discomfort. Gas and acids released by bacteria LARGE INTESTINE Undigested lactose enters the large intestine
Exclusion diets TREE NUTS For people who suffer from a food allergy or intolerance, often the only treatment Tree nuts EGGS is to avoid the trigger food. Unfortunately, include cashews, brazil if they aren’t careful, this can lead to nuts, hazelnuts, walnuts, Egg is one of deficiencies in certain nutrients. and almonds, but not the most common peanuts, which are legumes. food allergens, particularly Allergies and intolerances People with tree nut allergies in young children. Fortunately, are usually sensitive to most children grow out of egg allergy by the time they reach most tree nuts. double digits. The body’s adverse immune response to proteins in certain foods can lead to a variety of allergic symptoms, from MUSTARD itching and rash, to nausea and anaphylactic shock. Food allergies affect more than 1 in 20 children but are less common in adults. In cases of food intolerance, symptoms Although very rare, mustard allergy arise from deficiency of certain digestive enzymes (as is is thought to be more the case with lactose intolerance), or the direct common in countries where action of chemicals within foods. LUPIN mustard—including mustard seeds—plays a large part in the FOOD ALLERGIES Lupin is a VARY REGIONALLY. legume in the same diet, such as France. IN ASIA, RICE family as peanuts, and like peanuts, its allergens can trigger anaphylaxis. Lupin flour ALLERGY IS ONE OF and seeds are sometimes used MOLLUSKS in baking and pasta. THE MOST COMMON Mollusks Trigger foods include scallops, Any preprepared food or drink sold in Europe must mussels, clams, oysters, clearly state on the label if it contains any of the ingredients octopus, and squid. They shown here (right). However, in other parts of the world, have only quite recently been different trigger foods are more common. added to the EU list for mandatory labeling of DAIRY NUTRIENTS ALTERNATIVE SOURCES allergens. Calcium Leafy green vegetables, MILK SOYBEANS Zinc fortified milk alternatives Vitamin B2 Red meat, whole grains Milk from cows Soybeans are Vitamin D Beef liver, lamb, almonds (or other animals) is widely used in Sunlight, oily fish, fortified milk one of the most common processed foods and in alternatives, fortified cereals allergic triggers, particularly Asian sauces. Allergy to in children. It is distinct from soybeans is quite common, lactose intolerance, which is especially in young children, but symptoms are nonallergic. typically mild. Dairy-free diet Cutting out dairy means losing out on a valuable source of nutirents, but it is fairly easy to swap cow’s milk products for alternatives made with soy, rice, and nut milks. There are plenty of alternatives to replace the calcium, zinc, and vitamins in dairy foods.
210 211DIET Exclusion diets GLUTEN NUTRIENTS IN ALTERNATIVE SOURCES GLUTEN-RICH FOODS Beans, fruit, vegetables, nuts Intolerance to gluten, found in Fiber wheat, rye, and barley, is PEANUTS spreading around the world, B vitamins Non-gluten-containing probably due to the whole grains such as brown One of the Westernization of diets, and rice and quinoa most common food the replacement of rice with allergies, peanut allergy wheat products. Vitamin D Sunlight, oily fish, fortified has been on the rise in milk products children in the last few years. Exposure to even trace amounts Folic acid Leafy green vegetables, beans can cause potentially fatal Iron Meat, leafy green vegetables anaphylaxis. FISH Calcium Dairy foods Fish Zinc Red meat, dairy foods including tuna, salmon, and halibut, Magnesium Leafy green vegetables, nuts, can cause severe allergic and seeds reactions in some people. These should not be confused CRUSTACEANS Gluten-free diets with our reaction to histamine A wide range of gluten-free foods is available, released by Vibrio bacteria— Thought to but a diet free of gluten can be short of nutrients. that is food poisoning. result in the greatest There are many natural and unprocessed foods number of severe allergic that can help you to remedy any deficiencies in SESAME SEEDS reactions, the allergy to crabs, fiber, vitamins, and minerals. lobsters, and shrimp, usually Sesame seeds appears during adulthood. are also eaten in the form of flour, oil, and Diet dangers paste. Although relatively uncommon, sesame allergy There is a risk that exclusion diets is more common in people allergic to other foods. can lead to malnutrition, particularly in children. If a child doesn’t receive the right balance of proteins, carbohydrates, and fats, as well as essential vitamins and minerals, their growth and development may be affected, and they SULFITES are at risk of various illnesses. It is important that the parents of children with allergies understand Sulfites are CELERY how to replace any nutrients missing from used as preservatives their child’s diet. in products such as pickled Exposure to and dried foods and alcoholic celeriac and celery can Stunted growth drinks. Although uncommon, trigger severe symptoms, Children with multiple food intolerance can produce including anaphylactic shock. allergies have been shown to asthmalike symptoms. It is most common in be shorter, on average, than others their age, suggesting European countries. diet-related growth problems. NORMAL STUNTED Rickets Cases of children developing rickets (osteomalacia) through inadequate calcium and deformed leg bones vitamin D intake because of milk allergy have been seen. AFFECTED CHILD
Diet and blood pressure Along with other lifestyle choices, what we eat and drink can have a direct effect on our blood pressure. High blood pressure— also known as hypertension—is a long-term medical condition that can lead to cardiovascular disease. However, this “silent killer” is both preventable and treatable. 180+ Stages of hypertension Blood pressure is reported HIGH: STAGE 2 HYPERTENSION in millimeters of mercury (mm Hg). As it rises above the 160 normal level, it reaches a stage of prehypertension before HIGH: STAGE 1 HYPERTENSION two stages of hypertension. At stage 2, the risk of 140 developing cardiovascular diseases is very high. PREHYPERTENSION SYSTOLIC BLOOD PRESSURE (MM HG) 120 NORMAL Blood pressure readings Measuring blood pressure as the heart beats gives systolic (beating) and diastolic (rest) values. An average healthy blood pressure reading is below 120/80. A person has hypertension if their reading is higher than this over a sustained period. Factors that cause blood pressure to rise include eating too much salt, being obese, drinking too much alcohol, and smoking. It can be countered through dietary and lifestyle changes. 90 LOW 40 60 80 90 100 120 40 DIASTOLIC BLOOD PRESSURE (MM HG)
212 213DIETS Diet and blood pressure Why is high blood pressure dangerous? Although there are rarely any symptoms of high blood WHAT IF I pressure, if it is left untreated the heart gradually CAN’T GIVE UP SALT? becomes enlarged and less efficient. Slowly, the blood vessels, kidneys, eyes, and other parts of the body can Alternatives to regular salt are become damaged. As blood pressure goes up, artery available. These usually contain walls become thicker and stronger and arteries potassium rather than sodium. become narrower, threatening to slow or even stop However, too much potassium blood flow. This increases the risk of heart attack, heart failure, and stroke. can be dangerous for people Thick, tense with kidney problems. muscle during systole (heart Blood cell Thinner, relaxed muscle Much-thickened Restricted pumping) during diastole (heart muscle tenses blood flow at rest) during systole BLOOD IN ARTERY NORMAL BLOOD PRESSURE CHRONIC HIGH BLOOD PRESSURE Healthy arteries Narrowing arteries A normal blood pressure changes from a high, as the heart If your blood pressure is high, your arteries have to work harder pumps, to a low, when it relaxes. The muscles in our artery walls to resist the pressure, so their walls become stronger and thicker. respond to these fluctuations by tensing and relaxing in rhythm. As your arteries get narrower, blood pressure rises further. Dietary solutions NUTS, SEEDS, SWEETS WHOLE LEGUMES <1 6–8 The best ways to reduce blood pressure are to reduce your salt intake and maintain a healthy LPEO<AU2NLTMREY,AFT,ISH <1 GRAIN weight. Sodium is the dangerous ingredient in salt, and switching to salt with low sodium can help. FATS, OILS LOW-FAT More broadly, the DASH (Dietary Approaches to 2–3 2–3 Stop Hypertension) diet is an initiative in the US that focuses on eating more fruit, vegetables, and whole DAIRY grains, as well as reducing salt, saturated fats, and alcohol. Although it wasn’t designed for weight loss, it can easily be adapted by reducing portion sizes. The DASH diet has been shown to lower blood pressure, reduce cholesterol, and improve insulin sensitivity. WORLDWIDE, THE FRU4IT–6 VEG4–E5TABLES NUMBER OF PEOPLE Food group portions WITH UNCONTROLLED The DASH diet offers a guide to how many portions of each food HYPERTENSION group to eat each day. For nuts, seeds, and legumes, the advised EXCEEDS 1 BILLION dose is 4–5 portions a week; for sweets, 5 portions or fewer a week.
HIGH LDL-, HIGH HDL-CHOLESTEROL Meat Saturated fats Nuts These fats tend to increase KEY Milk levels of both bad and good cholesterol in blood. Until LDL (bad) recently, experts thought that cholesterol the good cholesterol could compensate for the bad HDL (good) cholesterol, but now it is cholesterol thought this isn’t true. Some types of saturated fats are HIGH LDL-, LOW HDL-CHOLESTEROL harmful in certain people so it is worth limiting intake to less than 7–10 percent of total energy intake. Trans fats Trans fats, which are created by hydrogenating vegetable oils, raise bad cholesterol levels and lower good LOW LDL-, H Cookies cholesterol levels. People eat them in cakes, cookies, margarine, and deep-fried foods. They are so bad for you that some authorities can find no IGH HDL-CHOLESTEROL safe amount of trans fats to recommend Cake in the diet, and some countries have gone as far as banning them altogether. Chips Unsaturated fats Fats and cholesterol Eating unsaturated fats can lower the level of bad Although fat is an important part of our cholesterol and raise levels diet, some fats are healthier than others. Olive oil of good cholesterol. This Eating different types of fats affects the levels of the different types of leads to a range of benefits cholesterol in our blood (see pp.30–31), such as lower blood pressure with negative and positive effects. While and a lower risk of heart “bad” cholesterol contributes to the build disease. Olive oil is a good up of fatty deposits on our artery walls, Avocado source of monounsaturated “good” cholesterol transports cholesterol to the liver for removal. fat, and its beneficial effects on cholesterol levels may be key to the healthiness Salmon of the Mediterranean diet. Heart disease IS HEART DISEASE and stroke REVERSIBLE? Diet plays a major role in the development of heart By making radical diet and disease—the leading cause of death in the developed lifestyle changes some people world. By eating less of some types of foods and more have been known to halt the of others, we can combat the key conditions that lead development of heart disease to heart disease and stroke, including high cholesterol levels, high blood pressure, and obesity. and achieve improved blood flow to the heart.
214 215DIETS Heart disease and stroke Cholesterol and heart disease 610,000 In people with a diet low in antioxidants (found THE NUMBER OF in fruit and vegetables), too much cholesterol may AMERICANS WHO lead to a buildup of fatty deposits (atheroma) on DIE EACH YEAR the walls of the arteries. The body reacts with an FROM HEART DISEASE inflammatory response that swells and thickens the artery walls. This restricts blood flow, and OD VESSEL Blood cell tissues beyond that point are starved of oxygen. If this happens in the coronary LDL (bad) cholesterol carries arteries it can lead to the fat to the artery wall death of heart tissue. If enough dies, a heart attack or heart failure can result. HEART BLO Thickening artery wall Heart tissue Buildup of starved of fatty deposit oxygen dies (atheroma) HDL (good) FOOD FOR THE HEART AND BRAIN cholesterol Narrowed artery Certain foods can have a beneficial effect on the heart by Restricted blood flow making the blood less viscous. Intake of omega-3 fatty acids Bad cholesterol carries fats to the reduces the “stickiness” of blood, reducing the risk of clotting. artery wall allowing fatty deposits Garlic is thought to have the same effect. Other foods are able to form, narrowing the artery. Fatty to make blood vessels widen (dilate), allowing more blood to deposits may eventually rupture and pass. Leafy greens, which encourage the production of nitric cause blood clots that can completely oxide, are known to relax the blood vessels in this way. It may block blood vessels. When this type of also be one mechanism by which moderate alcohol intake may obstruction occurs in arteries supplying lower the risk of heart disease and stroke (see p.165). the brain, it results in a stroke. GARLIC LEAFY GREENS
Diabetes Pericardial fat Insulin is a hormone that helps muscle and fat cells absorb glucose. Diabetes occurs when the pancreas can’t produce insulin or cells become insensitive to it. If cells can’t absorb glucose, blood sugar levels can become dangerously high. Types 1 and 2 1 Visceral fat builds up Visceral, or “deep,” In type 1 diabetes, insulin-producing cells in the fat builds up around and HEART pancreas are damaged and produce little or no insulin. In type 2, the pancreas secretes insulin, but muscle within muscles and organs, and fat cells do not respond to it by absorbing glucose, and lines the arteries over and blood sugar levels become high. While type 1 years or decades. BLOOD usually starts early in life, type 2 tends to develop VESSEL later, and is linked to obesity. Type 2 diabetes, which accounts for 90 percent of cases, is on the rise globally. Fatty liver LIVER Vision Increased Long-term risks Visceral problems and risk of stroke Over time, high blood adipose sugar levels can harm blindness Increased blood vessels supplying fat risk of heart tissues all over the body. disease This can result in damage INTESTINES to the eyes and kidneys, and can also increase the risk of various cardiovascular diseases. Kidney failure Intra- muscular fat WHY DO WOMEN GET DIABETES DURING PREGNANCY? The hormones that are produced during pregnancy can sometimes counteract the effects of insulin, resulting Foot ulcers in gestational diabetes. and infections In most cases, it is only temporary.
216 217DIETS Diabetes 2 Glucose enters system 3 How insulin should work Prevention and Glucose enters the The pancreas produces insulin management bloodstream through the digestion when blood glucose levels rise. of carbohydrates in food. This Insulin triggers receptors on muscle Losing weight is the single best triggers cells in the pancreas to and fat cells, opening channels in the thing you can do to prevent and secrete insulin into the blood. cell membrane and letting glucose in. control type 2 diabetes. There is evidence that a Mediterranean diet Insulin molecule Glucose flows in can help to stabilize blood sugar opens muscle cell through open channel levels, and some research suggests low-carbohydrate, low-GI, and Glucose NG Buildup of fat causes high-protein diets can also help. molecule NSULIN WORKI insulin resistance INSULIN RE SISTANT 4 How insulin DO DON’T can fail In muscle cells with Eat plenty of non- Eat too many processed I a buildup of fat, the starchy fruit and foods that have hidden vegetables daily carbs and calories insulin receptors in the cell membranes become resistant and block them. The Have an eating plan and Overeat, as this can glucose channels become familiar with cause spikes in blood do not open. the glycemic index sugar levels Buildup of glucose not Drink plenty of water, Skip meals or eat at absorbed by muscle cell which helps to dilute irregular times to avoid the blood blood sugar dips 5 Insulin overload Watch out for hidden Drink much alcohol, as As levels of glucose continue carbohydrates, this can keep blood especially in fruit drinks sugar level elevated Flood of insulin to rise, cells in the pancreas Choose healthy fat Eat too much salt, as in blood increase their production of insulin, and low-sugar food high blood pressure is resulting in insulin overload. alternatives common in diabetics Insulin molecule Obesity and insulin resistance COUNTING CARBS Obesity is the single best predictor of type 2 diabetes. The global People with type 1 diabetes, and those rates of each have risen to an almost epidemic state. Most people taking medication for type 2 diabetes, who are obese not only have fat in the outwardly obvious fat stores, may choose to count the carbohydrate but also hidden throughout their bodies. This fat increases the content of each meal or snack they eat, resistance of muscle and fat cells to insulin, so that the cells fail so they know how much insulin to give to respond and do not absorb glucose, no matter how high insulin themselves afterward. levels become. Sugar then builds up in the blood—so much so that Overmedication can lead it can make the blood thick, syrupy, and prone to infection. to a “hypo”—an episode of low blood sugar that can THE WORLD HEALTH be very dangerous. ORGANIZATION PREDICTS THAT DEATHS FROM DIABETES WILL RISE BY MORE THAN 50 PERCENT OVER THE NEXT DECADE
Cancer, osteoporosis, MOU TH and anemia ESOPHAGUSBOWEL What we choose to eat and drink directly affects our health and, ultimately, our longevity. By consuming more of some foods and drinks but restricting others, we can reduce the risks of developing diseases and conditions including Foods that hurt or heal cancer, osteoporosis, and anemia. By having a healthy, balanced diet you can reasonably Cancer Fish oils and expect to reduce your risk of omega-3 fats developing cancer. However, There is a seemingly constant turnover of Several studies have there is increasingly strong foods and drinks that make the headlines produced evidence to scientific evidence that certain for either causing or curing cancer. suggest that eating increased foods and drinks can cause, However, interpretation of scientific amounts of oily fish, which are or help to prevent, specific findings can be subjective, and claims for rich in omega-3 fatty acids, types of cancer. “evidence” are often misleading. Cancer is decreases the risk of breast a hugely diverse range of diseases, and the cancer in women. causes and treatment of one type may be very different from another. Nevertheless, there are a few dietary choices we can make that most experts believe will reduce LIVER our risk of developing a range of cancers and improve our general health. Fruit and vegetables EXPERTS BELIEVE THAT High fruit intake 1 IN 10 CANCER CASES lowers the risk of COULD BE PREVENTED developing upper gastro- BY HEALTHY DIETS intestinal tract cancer, while both fruit and vegetables reduce the risk of developing bowel cancer. SMALL INTESTINE WHERE DO THESE Fiber FINDINGS COME FROM? Increased fiber intake has been Most of these findings come linked with a reduced from the EPIC study, which has chance of developing been following more than half cancers including those of a million people across Europe the bowel and liver. Fiber helps since the mid-1990s, looking to keep your bowels moving, which may prevent the at their diets and buildup of cancer-causing health. compounds.
218 219DIETS Cancer, osteoporosis, and anemia Saturated fats Osteoporosis There is some evidence to suggest that increased saturated If bones do not take up or retain enough calcium, fat intake leads to an increased they can become weak, with the increased risk of risk of certain types of breast fractures—a condition called osteoporosis. Although cancer in women. it is more common in older people, the process can start much earlier. While hormone levels play a major Alcohol role, a poor diet can be a contributing factor. Even at moderate levels, alcohol AMIN D CALCIU increases the risk of several kinds of VIT VIT M cancer. These include FOL Cancer cancers of the mouth, Eggs Fortified Dairy cells larynx, esophagus, liver, Fish cereals Leafy breast, and bowel. Bony greens BREAST fish STOMACH Foods for bone health Osteoporosis can be prevented by eating a healthy diet containing foods rich in vitamin D and calcium. These include dairy products, fish, and leafy greens. Salt Anemia Salt intake has been linked to Iron-deficiency anemia occurs when the body does not stomach cancer. This could receive enough iron to produce enough red blood cells for be because it damages the healthy circulation. A lack of vitamin B12 or B9 (folic acid) stomach lining, or because it can cause macrocytic anemia—a rarer form in which red makes it more sensitive to other blood cells are too large and don’t work properly. cancer-causing chemicals. IRON Red and processed AMIN B12 IC ACID meat Long blamed for Red meat Dark leafy greens causing bowel and stomach cancers, the role of Poultry Whole/fortified red meat in cancer has been cereals cast into doubt by new studies. Nitrites in processed meat are Nuts and seeds still regarded as a risk factor. Preventing anemia You can prevent the onset of anemia by including sufficient iron-rich food in your diet, as well as foods rich in vitamin B12 and B9.
What to eat during Manganese pregnancy A mineral found in many different foods, manganese Diet plays an important part in the Magnesium SPINEaids the formation of bone,BLOOD VESSEL health of a woman and her baby Magnesium aids fetal SPINAL CORDcartilage, and connective during pregnancy. Eating well will tissues in the growing fetus. help the fetus to develop healthily bone and muscle and ensure that its mother’s body development, and can PLACENTA is in peak condition for the birth. help prevent the uterus BONES Food to enjoy from contracting Iodine prematurely. Iodine is important Eating the right balance of different food for the growth and types is essential for a healthy pregnancy. Folate development of the brain and To keep energy levels high, mothers-to-be Folic acid (vitamin nervous system. Deficiency can eat more unrefined starches, such as B9) is essential for the can cause cognitive whole grains. Good sources of protein and development of an unborn and developmental calcium, including lean meats and dairy baby. Deficiencies in the products, are vital for supporting the baby’s mother can increase the problems. growth and development. Eating at least five risk of her baby’s spinal portions of fruit and vegetables a day helps cord failing to form mothers get enough vitamins and minerals properly, leading to to keep them and their growing babies in optimum health. A balanced diet will also spina bifida. help to ensure that weight gain during pregnancy remains within healthy limits. Good for mother and child Copper Particular micronutrients present in different foods have Copper plays an specific health benefits for a mother and her unborn baby. important role in the In most cases these can be obtained naturally through formation of a baby’s eating sufficient amounts of certain foods, but for some heart, blood vessels, vitamins and minerals—as in the case of folate (folic acid, blood cells, and skeletal or vitamin B9)—dietary supplements are recommended. and nervous systems. KEY Eggs Mushrooms Whole grains Bread Rice Peanuts Peas Cashews Milk Broccoli Avocados Soybean Bananas Cheese Fruit
220 221DIETS What to eat during pregnancy Calcium Foods to avoid Calcium is an essential mineral in the formation Some foods that can usually be eaten as part of a healthy diet of bones and teeth, so pose a risk during pregnancy, either because they carry a higher ensuring you have enough than average risk of food poisoning or because they contain calcium in your diet is specific organisms or toxins that can be passed on from the mother to the unborn baby and affect its development. crucial during pregnancy. Caffeine Liver Iron Consumption of caffeine Liver, and some sausages and Both the placenta should be limited as high patés, contain high levels of and the growing fetus levels have been linked to low vitamin A, which can cause place heavy demands on birth weight and miscarriage. birth defects. the mother’s supply of iron. Iron intake must Alcohol Fish increase to supply the Alcohol is thought to be High levels of pollutants mean placenta and to create unsafe for the developing that big predatory fish should the fetus’s new baby, so expectant mothers be avoided and consumption blood cells. should avoid it completely. of oily fish should be limited. Soft and blue cheese Undercooked meat Exposure to pathogens like Eating undercooked meat listeria from unpasteurized can lead to bacterial or dairy products can cause parasitic infections that can miscarriage and stillbirth. seriously harm a fetus. Game meat Multivitamins Game meat that has been It’s best to avoid multivitamins killed with lead shot should that contain high levels of be avoided due to the health vitamin A, since this can be risks posed by the lead. toxic to an unborn baby. BRAIN GESTATIONAL DIABETES WHAT CAUSES Choline FOOD CRAVINGS? Brought on by hormonal changes Only recently classified as an or simply the physical demands of Many women experience essential nutrient, choline is pregnancy, gestational diabetes food cravings and aversions key in the development of the occurs when the effects of insulin during pregnancy. These are brain and spinal cord. Like are counteracted and blood-sugar thought to be caused by the folate, it is thought to reduce levels become high. If left untreated, extreme hormonal changes there are increased risks of the the risk of neural defects. baby growing too large, that can affect a mother’s premature birth, and taste and smell. abnormal labor. Treatment involves PREGNANT tracking blood WOMEN ARE MUCH sugar and making MORE LIKELY TO dietary changes. CATCH INFECTIONS
Babies and children During the first years of life, nutrition is critical for DIETS MUST BE BROAD healthy development. Infants’ diets must provide the right balance of protein, fat, and carbohydrate, along Babies raised vegan or on other with vitamins and minerals including calcium and restricted diets must be carefully vitamin D for bones and vitamin A for developing eyes. monitored to ensure they get all the essential nutrients. Even getting Babies Cup of water offered enough calories can be difficult at meal times because vegan or vegetarian diets For the first 6 months, babies get almost have lower energy densities than everything they need from breast milk or Pureed food diets that include meat and fish. formula, although breast-fed babies may need introduced Plenty of protein sources must be extra vitamin D. After this, some of the milk included, along with adequate should gradually be replaced with solid food. vitamin B12, iron, and vitamin D. Puréed fruit and vegetables are good Supplements may be necessary. starting points, followed by chicken and other protein sources. KEY First solids Breast milk or Milk and dairy foods Babies often dislike a food the first formula still the time they taste it, so it is good to major part of the diet Other foods introduce new foods one at a time, repeating each one even if they react Meat, fish, and Mother produces dairy should colostrum for a few negatively. Offering food that is now form part days after giving birth, easy to hold helps babies learn of the diet then breast milk to feed themselves. 6—9 MONTHS Liquid diet Changing gut microbes Breast milk has the right By the end of their first year, the balance of nutrients for types of bacteria in the baby’s newborns, helps boost their immune system, and establishes gut begin to look more like their gut bacteria (see p.25). those in an adult’s. Before this Formula is usually made from time, they vary dramatically cow’s milk, but has higher whey between infants, depending on content and less casein protein the bacteria their environment to make it more similar to breast milk and easier to digest. has exposed them to. BIRTH—6 MONTHS 9—12 MONTHS
222 223DIETS Babies and children Young children Fruit juice can Breakfast cereal DO CHILDREN be given with is a good way to NEED SUPPLEMENTS? As the proportion of calories a meal, once combine grains from milk is reduced, a day and dairy in a meal young children tend to be encouraged to try lots of Babies and young children different foods. But their diets often can’t get all the vitamins should differ from adults’ in they need from milk and food. some ways. Too much fiber, for example, can fill small Vitamins A, C, and D are stomachs quickly, preventing usually recommended for children from eating enough children from 6 months calories. Protein (including dairy) is important. to 5 years. Starchy food, such as Growing needs butternut squash and A healthy diet for a 2–to-5-year-old should grains should now be include three to four servings of starchy foods, the same of fruit and veg, and two servings of a part of meals protein. Skim milk or other dairy products (such as yogurt and cheese) can replace the whole milk. These are a good source of protein and calcium, needed for growing bones. 2—5 YEARS Diet continues to Grown-up foods include protein, By 5 years, children’s diets such as chicken are, ideally, varied and Milk alternatives Infant can start similar to an adult’s. Salt From 1 year old, the baby’s intestines drinking whole are able to digest the higher casein cow’s milk should not be added content of whole cow’s milk. Fortified because of the potential alternatives such as soy milk can be Low-fat (1 percent) harmful effect on kidneys. used instead, but growth should be milk can be introduced Low-fat or skim milk is now fine, since children monitored because they contain to replace skim milk will get enough calories fewer calories than whole cow’s milk. from food. 5+ YEARS 1—2 YEARS PORTION SIZES RICE MILK SHOULD NOT With childhood obesity rising, BE GIVEN TO CHILDREN portion sizes are important. For UNDER 5 AS THE ARSENIC a child under 3–4, a portion might LEVELS ARE TOO HIGH be one slice of toast, 1/2oz (15g) of oats, half an apple, or one egg, but this depends on activity levels.
Eating disorders HOW LONG DO EATING DISORDERS Eating disorders are mental health conditions involving USUALLY LAST? an unhealthy relationship with food and abnormal Research carried out in eating habits. They have a devastating impact on the Australia suggests that the day-to-day lives of millions of people and can cause average length of time that a wide range of serious medical problems. someone suffers with anorexia and bulimia is eight and Three main types five years respectively. People with anorexia believe themselves to be fat and starve themselves to keep their weight as low as possible. Bulimia Anxiety, including feelings involves some of the same attitudes as anorexia, but people of shame and guilt alternate cycles of binge eating with purging—either vomiting or taking laxatives. Binge eating is compulsively BRAIN eating vast quantities of food, often without feeling hungry. 1 IN 100 FEMALES IN THE HEART Higher risk of heart DEVELOPED WORLD WILL PANCREAS FAT TISSUE disease and heart DEVELOP ANOREXIA attack KIDNEY Causes Increased levels of body fat can lead Eating disorders usually involve a degree of body to diabetes dysmorphic disorder—a negative distortion of how an individual sees themselves. There may Higher risk of be a combination of factors that contribute to this. pancreatitis and diabetes LOW SELF-ESTEEM Chronic kidney BONES People with low problems, or even Increased chance self-esteem often of developing have a negative body kidney failure osteoarthritis image. As a result, they in the joints may either find CULTURE GENETICS it hard to value and take care of their body or feel the drastic need to change it. Eating disorders An emphasis on Binge eating run in families, so may thinness in the beauty Eating large volumes of food over short periods can place be passed on genetically, stereotypes presented in significant stress on the body’s digestive system. Most sufferers or by learning attitudes the mass media has distorted are likely to be overweight or obese, so suffer associated health toward food. People who the idea of an ideal body problems, including cardiovascular disease and diabetes. have a close relative with an shape and encouraged eating disorder are much more likely to develop people to base self- value on outward one themselves. appearance.
224 225DIETS Eating disorders FEMALE BIAS 20% 8% KEY 80% 92% Percentage Eating disorders are much more BINGE EATING ANOREXIA of cases who common in women than in men. This are women may reflect that they are more sensitive to the cultural pressures that can lead to Percentage eating disorders. The proportion of men of cases who in cases of binge eating is more than are men twice as high as in anorexia. Dizziness, HAIR Hair becomes dry High incidence MOUTH depression, anxiety, BRAIN and brittle and of gum disease, and low self-esteem may fall out sensitive teeth, THROAT HEART are common MUSCLES tooth erosion, MUSCLES Sore throat and and decay inflammation of Muscles the esophagus become weak Muscle protein of the are common heart itself can even and wasted HEART begin to break down Stomach pain, to be used as fuel, ulceration, and NAILS weakening the heart STOMACH bloating are Nails become BOWEL common dry and brittle BOWEL HORMONES Bloating and NAILS HORMONES constipation SKIN are common SKIN Constipation, diarrhea, and cramps In women, uterus may develop due to shrinks and periods overuse of laxatives stop; it becomes harder to conceive Skin becomes Increased risk dry and scaley, of osteoporosis and fine downy hair may appear BONES BONES Anorexia Bulimia Severe calorie restriction and a deficiency of essential dietary Although some people with bulimia may maintain a normal body nutrients can have a traumatic effect on the body, causing serious weight, potentially they can suffer from all the health problems health problems. Often these effects are irreversible, and if it linked with anorexia. However, they may also have additional continues for a sustained period, anorexia is life-threatening. problems associated with frequent vomiting and laxative use.
FOOD AND ENVIRONMENT
Feeding the world The scale and efficiency of food production has improved Biotechnologies over the past 60 years, due to technological advances, and High-yield, drought-resistant in response to a growing population. Some people, however, hybrid crops and massive still go hungry. Hunger will likely stay with us, as the more application of fertilizers, affluent people among the world’s growing population pesticides, herbicides, increasingly gain a taste for meat. Eating meat takes and other biochemicals up a disproportionate amount of Earth’s resources. dramatically increased yields. Social plans Green revolution Mechanical improvements Consolidation of small farms into Large scale mechanization giant ones, and small businesses In the 1960s and 70s there was widespread concern of agriculture (such as irrigation into transnational agribusinesses, about a looming mismatch between food supply and machines) made intensive created economies of a global demand on a global basis in the face of a skyrocketing farming possible on a vast scale and improved yields. global population. Books such as Stanford University scale, boosting yields. professor Paul Ehrlich’s 1968 best-seller, The Population Bomb, predicted a looming famine crisis. The success of the Green Revolution saw a radical increase in agricultural productivity. Improvements in agricultural machinery, biotechnological chemicals, and social collaboration were made that averted the crisis. Rise in meat consumption Global meat and cereal consumption Despite the Green Revolution, we still face food This graph shows a global rise sustainability challenges—one of which is meat eating. in total consumption of meat Global demand for meat has increased five-fold in the and cereals to the present day last 50 years. While meat is stable at around 30 percent and projected up to 2020. of the diet in the West, in some developing countries, the rate of meat consumption is skyrocketing. Farming livestock relies heavily on the availability of water, land, feed, fertilizer, fuel, and waste disposal capacity—and the pressure on these resources is climbing. KEY Meat consumption per capita Cereal consumption per capita YEAR 2008 2010 2012 2006
228 229FOOD AND ENVIRONMENT Feeding the world 30% DGERVAEINLOPPREODDCUOCUENDTIRNIES 800 MILLION 10 FEEDS 8 HUMANS THE NUMBER OF PEOPLE 70% IN THE WORLD WHO DO NOT FEEDS GET ENOUGH FOOD LIVESTOCK Animal feed WHAT IS THE Worldwide, animals (mainly cows) MOST SUSTAINABLE consume an estimated one-third or more of human grain production. In TYPE OF FOOD? developed countries, the proportion is even higher, at around 70 percent Probably beans—they add of grain fed to livestock. nitrogen back into soil, reducing or eliminating the PERCENT CHANGE SINCE 2006 need for fossil fuel-based fertilizers, reducing carbon dioxide emissions. 400g (14oz) meat, 1 meal, 545 6 or two large steaks calories each 4 Efficiency of eating animals 1kg 200g TWO PEOPLE In the US, cows eat livestock feed (grain). 1kg 1kg (7oz) A cow has to consume more than 200g 7kg (15lb) of grain to gain 1kg (21⁄4lb) 1kg (7oz) in weight, and 1kg of cow converts 1kg 1kg to around 400g (14oz) of trimmed, deboned cuts. Feeding cows grass 1kg BEEF STEAK is more efficient—but is still far less 7KG (15LB) BAGS OF GRAIN efficient than simply eating plants. 11 people would get 545 calories each Efficiency of eating plants 1kg 11 PEOPLE 2 Comparatively, 7kg (15lb) of grain could 1kg 1kg 2018 feed about 11 people for a single meal. 0 Growing grain uses less space, energy, 1kg 2020 and labor than farming animals. 1kg 1kg 1kg 7KG (15LB) BAGS OF GRAIN 2014 2016
Intensive or organic? SUNLIGHT Intensive farming on an industrial scale has helped to keep pace with a rapidly growing population, but at a cost to the natural environment. In response, the emergence of organic food appeals to our appetites, conscience, and health. Intensive farming In the 1960s, the Green Revolution saw biochemical advances in agriculture (see p.228)—such as fertilizers that speed crop growth and pesticides that protect crops from pests—both of which help produce much higher yields. However, intensive farming has severe impacts on surrounding ecosystems—fertilizers and pesticides can leak into the water and soil and affect wild plants and animals. Not only that, but there is a concern that certain foods may contain pesticide residues— remnants of the toxic chemicals applied to crops. Intensive farming KEY Farming large areas means farmers have Pesticides to apply fertilizer and pesticide over entire fields and in large amounts to ensure that Fertilizer the target crop plants get enough. 1 Fertilizer runoff 2 Algal blooms Excess fertilizer from Fertilizer runoff can also stimulate overgrowth of algae, forming algal blooms. industrial farms is flushed off fields This dense vegetation can collect on a lake’s by rain, and into rivers and lakes. This causes wild plants to overgrow. surface. Algal blooms can kill off entire aquatic ecosystems by using all of the lake’s oxygen, and also block sunlight from reaching the lake floor. Plants on lake CROPS bank overgrow FERTILIZER RUNOFF ALGAL BLOOM PESTICIDE R BEES Pesticides can harm bees 1 Pesticide runoff Pesticides sit on the plants that we will eventually eat. These chemicals can kill the bees that pollinate many UNOFF Plants at bottom of lake crops. Pesticide as runoff can even be WORMS die without sunlight carried by rain into lakes and ingested by SUNLIGHT BLOCKED invertebrates (such as worms) that live there.
230 231FOOD AND ENVIRONMENT Intensive or organic? 40 PERCENT OF THE What is organic food? NO ARTICIAL WORLD’S POPULATION FERTILIZER RELIES ON CROPS Organic foods are crops that are grown GROWN USING without the help of artificial fertilizer NO ARTIFICIAL NITROGEN and pesticides, and processed and stored PESTICIDES FERTILIZER without chemical fumigants. Instead of these, natural alternatives are used— Nutritional difference CAN MEAT manure is a natural fertilizer, and natural There is debate over whether BE ORGANIC? predators, such as ladybugs, can be used organic food is actually Meat can be organic, if to control pests, such as crop-damaging nutritionally superior to livestock are fed on organically aphids. Standards of what constitutes nonorganic food, with several grown feed, allowed to go organic food can vary. Organic food is studies casting doubt on the outside, not given growth appealing for those concerned about their claims. A review in 2014 found hormones, and given health, because they are likely to have that the levels of six types of antibiotics only if the much lower levels of pesticide residue. antioxidant (see pp.110–111), animal is sick. on average, were higher and 69% 51% pesticide residues lower in Pesticide in food higher higher organic foods. can affect our health 50% higher 19% 26% 28% higher higher higher FLAVANONES PHENOLIC ACIDS FLAVANOLS FLAVONES ANTHOCYANINS STILBENES THE PRICE OF ORGANIC FOODS Organic food is more expensive TRAINING because yields are generally lower 2 Up the food chain and overhead costs are higher. Ingested pesticides are For instance, organic dairy yields concentrated up the food chain. Worms are generally one-third lower than may only contain tiny amounts, but if conventional ones—so organic food fish eat enough of them, then the fish prices are raised in order to make a DISTRIBUTION PROCESSING profit. Extra costs can include farmer can contain more pesticide. Animals or training, the extra cost of processing even humans at the top of the food and storing without chemical chain can accumulate large amounts. fumigants, a shorter shelf life of crops, and the costs associated with a higher instance of spoilage as a result. PACKAGING STORING COSTS
Factory farmed or free-range? Intensive livestock rearing methods make meat cheaper Living space and more widely available, but there are ethical issues A hen can be reared under various to consider. Intensive farming has consequences for regimes (see opposite), and the animal welfare and can even influence food nutrition. amount of space that the animal can inhabit during its lifetime will Ethics of intensive rearing vary depending on the country. These are average figures from a Intensive livestock agriculture on a large scale can be attributed to the farm in Austin, Texas. explosive growth of confined animal feeding operations, or CAFOs. These factory farms have very high numbers and densities of animals, Free-range hens confined in small areas and fed grain with many enhancers and have an average of additives, such as antibiotics and hormones. CAFOs fuel the economy by producing large amounts of meat quickly, but at a great cost to 11sq ft (1sq m) in animal welfare, nutritional value (see p.71), and the environment. which to roam and Intensively farming animals causes them to suffer from stress for the majority of their lives and this ethical issue has influenced some the option of changes in animal rearing to keep livestock happier and healthier. going outside DO HAPPIER ANIMALS PRODUCE BETTER MEAT? Livestock such as cows and pigs Pasture-raised hens have an that are allowed to roam outside average of 108sq ft (10sq m) are generally less stressed—but it in which to roam is the natural diet of grasses and nuts they eat outside that makes their meat more nutritious. Natural diet Factory diet CORN FEED Pigs fed on their natural diet of Factory-farmed pigs are fed leaves and nuts generally have mainly on corn, which is very high more healthy omega-3 fatty in unhealthy polyunsaturated acids (see p.136) in their diet and omega-6 fatty acids (see p.136)— this means that their meat has high levels of this fatty acid can more omega-3 in it. also be found in their meat. OMEGA-3 GRASS OMEGA-6 FATTY ACIDS FATTY ACIDS
232 233FOOD AND ENVIRONMENT Factory farmed or free-range? PASTURE-RAISED Types of animal rearing FREE-RANGE There are a confusing number of terms that can Caged hens may be found on food. They describe farming practices, live in spaces only but many of them mean something different to what 1/2sq ft (450sq cm) consumers may assume they mean. Even within one big and do not category there can be wide variations. Although free- have the option to range sounds idyllic, chickens may still live in high roam outside densities and stay cooped up inside for most of their lives since they only have the option to go outside for a CAG small amount of time each day and some farmers never actively shepherd them onto pasture. There are voluntary farming practices that keep animals in good, healthy conditions, but producers must join a certified program set and checked by authorities to put welfare labels on their produce. The table below provides a guide to the most common labels found on beef or chicken. ED OVER 168 GASES TERMS DEFINITION ARE RELEASED IN CAFO Free-range Free-range standards may simply include WASTE, SOME OF WHICH having access—no matter how remote—to Barn-raised outdoor space, but animals may never ARE DANGEROUS Organic actually go outside. Chickens can live in CHEMICALS Grass-fed high densities and can be debeaked (have Pasture-raised their beaks removed) and cows can also OVERUSE OF ANTIBIOTICS live in high densities. Animals are not caged, but they are Some farmers give antibiotics to uninfected animals as restricted indoors, kept at a high density, a precaution against disease organsims, which thrive in are usually debeaked (for chickens), and are crowded conditions. Because growth is stunted while an not allowed to forage or eat grass. animal is ill, precautionary antibiotics increase the rate This primarily refers to organic feed, and to of weight gain on average, leading to higher meat the banning of antibiotics and hormones. production. This indiscriminate overuse of Food that is organic usually includes higher antibiotics, however, contributes to the welfare standards such as outdoor time and spread of antibiotic-resistant bacteria in no debeaking in chickens. both livestock and humans. These bacteria After weaning, animals are allowed to outcompete beneficial bacteria eat only grasses. Cows that eat their natural and can become “superbugs” diet of grass produce meat and milk for which we have no defense. (see p.89) that is more nutritious. This is similar to grass-fed, although some grain feed is allowed. Livestock are raised outdoors, eating a selection of nutrient- dense forage crops.
Fair trade A tiny number of enormous global corporations dominate ARE THERE each stage of the complex chain that brings food from ANY ALTERNATIVES? field to plate. Powerful businesses use their influence Some coffee roasters to maximize their share of profits, which keeps food negotiate one-to-one with producers, often in the developing world, in poverty. buyers (direct trade) as an Fair trade can help farmers and businesses alike. alternative to fair trade—they What is fair trade? do this for many reasons, including avoidance of The principle of fair trade can always be applied when doing business. fair trade certification However, food can only be labeled as fairly traded if companies join a fees. certification system that makes sure their supply chains follow strict guidelines. These include paying their farmers and workers fairly and providing farmers in the developing world the opportunity to sell their produce on the international market. Fair trade food gives consumers a chance to help farmers at the other end of the supply chain. Organizations that support fair trade work with millions of farmers around the world, especially those producing fruit, sugar, cocoa, tea, and coffee. FARM COOPERATIV IMPORTER 1 A farmer and some workers will 2 ETThe farm's profits are shared3Fair-trade importers minimize grow bananas on a fair-trade ESevenly between those in thethe number of middlemen taking a cut of the profit. certified farm (or plantation). The local community who areION Producers and ethical fair trade program provides the materials they members of the farm's investors may influence cooperative. need. distribution. TRANSPORTAT STORAGE SUPERMARK 4 Transportation of the bananas is 5 Bananas stored at about 57ºF 6 Most supermarkets now organized by liaising with the (14ºC) have extended shelf stock fair-trade produce, lives. This helps farmers sell their transportation networks of the produce despite seasonal, but the primary driver for greater retailers—especially big supermarkets. environmental, and economic representation of fairly traded foods is consumer choice fluctuations. and pressure.
234 235FOOD AND ENVIRONMENT Fair trade GLOBAL PRODUCERS BANANAS GROWN IN ECUADOR AND SOLD TO THE EU Much of the world's food supply P12R¢ICE This amount is divided among is controlled by a few relatively twice the number of workers large corporations. They oversee WO5R.K6E%RS than a fairly traded banana production, distribution, and gain FARMERS most of the profit. This means 14% 6W.O2R5K%ERS A large percentage they influence consumer tastes, is paid to a and, hence, demand—creating plantation owner a difficult-to-break cycle. PRICE PLANTATIO2N5%OWNER 25¢ SUPERMARKET This amount is distributed among half the workers of a banana traded conventionally Fairly traded banana A large TRANCSC1OP8EO%MR4RT%MITFAUITENIROISTNIES 2.4% TRANSPORTATION A larger proportion of the price percentage is 33% of a fairly traded banana is paid paid to farmers to the farmer and workers, despite distributing a portion to the local A lower percentage community and reserving a cut for is paid towards the fair-trade certifiers. The retailer benefits financially from a fairly transportation and traded banana so that they have the shipping incentive to promote fair trade. A lower percentage is EU6%TARIFF A large paid as an EU tariff IMPOR9T%ERS percentage is RETA4I1L%ER EU12T.A5%RIFF A lower percentage is paid toward paid to importers transportation A large percentage is and shipping paid to the retailer FAIRLY TRADED BANANA A high percentage R1IP4E.6N%ERSCONVENTIONAL BANANA is paid as an R8E.6T5A%ILER EU tariff Conventional banana Almost none of the banana's value produced by the conventional pathway is passed on to the farmworkers. There are multiple intermediate steps (within each breakdown) between producer and consumer, and the bananas take weeks to get from plantation to plate.
Food fraud HORSE-MEAT SCANDAL Food products are always in demand, but where In 2013, DNA testing revealed that there’s money to be made there’s an incentive to in several processed foods, such as cheat. Food fraud is perpetrated at a scale far hamburgers and preprepared beyond most people’s imagination, with the risk lasagne meals, a substantial of serious consequences for human health. proportion of ground meat claimed to be beef was actually horse. What is food fraud? Complex supply chains made it hard to verify the origins of meat. Food fraud can take many forms, including substitution, dilution, origin masking, artificial enhancement, mislabeling, theft and SUBSTIT UTION resale, brand counterfeiting, and intentional distribution of contaminated food. The scale of the problem is unprecedented, but the practice itself has been going on for centuries. TION MISLAB DILU TUNA TILAPIA WHEY VEG OIL When consumers and even retailers find it hard to identify a valuable product, it is easy for Milk is one of the foods most commonly affected fraudsters to substitute a cheaper by fraud. Diluting milk with cheap additives, alternative. A high proportion of foods such as whey and vegetable oils, saves served as tuna and wagyu beef, fraudsters money. Complex supply chains, for instance, are actually where milk from multiple sources something else. is mixed, makes fraud much easier. ADDITION ELING UNWANTED SAND GRASS MISLABELED HONEY Most perniciously, unwanted and sometimes A product can be more valuable based on its toxic additives are used to bulk out food, trick testing authorities, or as substitutes for more point of origin. Manuka honey from New Zealand commands a massive premium, expensive ingredients. For instance, tea may be adulterated with used leaves, leading to widespread mislabeling of non-Manuka honey as the lawn cuttings, colored sawdust, more expensive kind. and even sand.
236 237FOOD AND ENVIRONMENT Food fraud 1.7Slippery business TRILLION US DOLLARS In a survey in 2014–15, most of the olive oil consumed by Italians could not be accounted for by any known HOW MUCH FOOD FRAUD COST olive oil production, either domestic or international. THE FOOD INDUSTRYThe shortfall was most likely cheaper oil passed off as WORLDWIDE IN 2015 sought-after olive oil. 10 14,000S Italians consumed 14,000 tons of WHAT CAN PEOPLE DO CODNOSTMUOMENSPSTTIICON correctly labeled, domestically TO AVOID FOOD FRAUD? 0,000 TONS IMPORT produced olive oil You can look into the supply Italy imported 100,000 chains of the food that you buy— tons of correctly but this may be time consuming labeled, foreign olive oil if the supply chain is long. Buying from personally known A supply gap of 407,000 tons is suppliers that you trust not accounted for may be the answer. by known olive oil sources Olive oil fraud FAKE FISH? When the figures don’t add up, there can be A 2013 survey by the Oceana ocean circumstantial evidence of fraud. A case in protection group studied samples of fish point is olive oil in Italy. Italians are among on sale around the US, using DNA analysis the highest consumers of olive oil, but their to reveal whether the species matched the domestic production does not come close to label. They found that around one-third of matching this demand, especially since the samples were not what they claimed to be, majority is exported. Even the 100,000 tons with 28 different species being sold as red imported cannot account for the nearly half a snapper, for instance. million tons consumed. Analysis in 2014–15 showed that lower-quality oils had been mislabeled as extra-virgin olive oil. Fraudsters are known to be able to pull off this trick by adding colors and aromas. 407,000-TON SUPPLY GAP 521,000 TONS TOTAL CONSUMPTION Italians believe they Only 2 percent consumed 521,000 of seafood is tons of olive oil inspected for fraud in the US
Food waste The amount of food wasted worldwide could easily feed all of those going hungry on our 100% planet today. Food waste costs money and When food is wasted damages the environment, and can happen This graphic shows how much food produced at all stages of the food production process. on land is wasted at each stage. These are global figures; in developing countries there is more Effects of food waste waste toward the start of the process due to a lack of cooling and storage capabilities so more Food is wasted at every stage of the food is spoiled, while in developed countries, production and supply process, and this most waste occurs toward the end of the process because people are more able to afford to purchase and waste food. is a problem that affects both the developed and developing world. Food waste costs money and drives up food prices, and its environmental impact is severe—3.3 billion tons (3.3 billion metric tons) of greenhouse gases are released from food waste to the atmosphere every year. Water, energy, 67% and space is wasted in producing and distributing food that will never get –11.5% eaten—28 percent of the world’s agricultural land is devoted to growing wasted food, while food garbage rots and 5 Consumption gives off methane, a potent greenhouse gas. Much of food waste, especially in developed countries, occurs at the GLOBALLY, consumption stage, when food is thrown away after it is purchased or even after it is prepared. ONE-THIRD OF ALL –4% FOOD PRODUCED FOR HUMAN CONSUMPTION IS WASTED HOW TO REDUCE WASTE 78.5% Even individuals can help TOMATO CARROT 4 Distribution and market minimize waste. Steps include: POTATO Retailers throw away foods that planning meals; preparing food are not bought by shoppers and even in advance; freezing or reusing foods that are not aesthetically leftovers; shopping little and pleasing to consumers (such as often; buying food that is near strangely shaped vegetables). the end of its shelf life; buying produce loose rather than in multipacks; and buying oddly shaped fruit and vegetables (so supermarkets do not reject them).
238 239FOOD AND ENVIRONMENT Food waste 1 Agriculture 92% CAN FOOD Some farmers, especially those WASTE BE RECYCLED? in developing countries, may possess limited agricultural resources, Food waste can be composted infrastructure, and knowledge— into soil conditioner or fermented using microbes to create fertilizer. The gas emitted during fermentation can be collected and used to generate electricity. and this can lead to lower yields. –8% –8% 2 Postharvest and slaughter What food is wasted? Inappropriate storage techniques and poor chilling facilities may cause The biggest cause of waste is some food to go bad or spoil. perishability. Foods with the shortest shelf lives, or that are the most easily 84% damaged, are those that tend to get wasted the most. This means that –1.5% the more easily damaged fruit and vegetables and roots and tubers are wasted the most, followed by fish and seafood that have short shelf lives. Less meat is lost, but it takes more land to produce meat, which destroys natural habitats—so the environmental impact of this waste is greater. PERCENTAGE WASTED 45% 45% 30% FRUIT/ 3 Processing and packaging ROOTS/ FISH/ Mistakes in the processing VEG TUBERS SEAFOOD stage can lead to further waste. 82.5% For example, milk that has been incorrectly pasteurized (see p.84) may be discarded. 30% 20% 20% CEREALS DAIRY MEAT
Food miles Until recent years, diets were limited by seasonality and locality, but the pace of modern transportation means that a Western shopper can buy any food at any time—but at what cost to the environment? Local versus global DO GLOMBESATLOICCFGAOFHLOOBFODOADRPRRHPMOROEODRDUS UCCERS ERS USA NEI L HOME OD The local food movement is based on the drive to reduce the environmental impact of industrial agriculture. One of its most obvious goals is to reduce pollution caused by transporting food long distances from source to market—hence, the concept of food miles. In fact, the true impact of food miles is hard to unpick; for instance, having local produce delivered to your doorstep by a local supplier might produce more emissions than walking to the supermarket to buy food bulk-transported from abroad. MORE THAN 15 PERCENT The bull’s-eye diet OF THE FOODS Advocates of the local food movement have made this EATEN IN THE US simple guide that prompts consumers to think about the ARE IMPORTED zones of production they can support to reduce their environmental footprint. At the center is what you can grow in your own yard or even window box, while outer rings should contribute progressively less and less to your diet. Seasonality December January A major driver of increased food miles in mber Febr modern food consumption is the demand October beimyoSpntordratwEeudbSreotfrrrpoareiwmesber uary ries imported from Spain for food at all times of year, irrespective of Nove March whether it is in season. Fruits, for instance, naturally have limited seasonal availability September April in any one territory, but suppliers work around this natural constraint by importing Domestic strawberries (UK) foods from faraway sources, or by cold- storing fruit on a colossal scale (many gust June Ma “fresh” apples were actually picked y many months ago). July Au British strawberries UK strawberry growers have contrived to extend their domestic season greatly, but suppliers still turn to imports to keep shelves stocked for the other five months of the year.
240 241FOOD AND ENVIROMENT Food miles Sourcing ingredients for pork dumplings KEY One way to assess the cost of the Countries exporting the ingredients for siu mai transportation involved in producing a dish is to look at its “foodshed”—the equivalent of a (steamed pork dumplings) to Hong Kong watershed for a river—showing all the sources that contribute. A processed food such as siu Pork Shrimp mai (steamed pork dumplings) produced in Hong Kong can have a complex Rice Wheat for dumplings transnational foodshed. outer case Sesame oil NETHERLANDS CHINA KOREA GERMANY SPAIN ITALY SOUTH JAPAN HONG KONG THAILAND VIETNAM BRAZIL MALAYSIA NEW ZEALAND INDONESIA Do food miles really matter? CO2 EQUIVALANT EMISSIONS FROM PRODUCING HALF A POUND OF EACH FOOD Some experts doubt that food mileage is CO2 EMISIONS the most important part of food production. 0.13lb (59g) According to one estimate, transportation 0.15lb (68g) contributes just 3.6 percent to food-related 0.20lb (91g) energy use. The nature of your food makes a far bigger impact than where it comes from. 0.55lb (249g) Vegans have a carbon footprint dramatically 1.90lb (862g) lower than meat eaters, because meat takes so 7.40lb (3,357g) much more energy to produce. The local food movement in fact targets industrial agriculture POTATO APPLES ASPARAGUS CHICKEN PIG BEEF rather than solely minimizing food miles.
Genetically SHOULD GM modified foods FOODS BE LABELED? The hype, discord, and intentionally misleading This is subject to fierce information surrounding genetically modified foods, debate. Advocates say it gives or simply GM foods, obscures the reasoned debate consumers more control and necessary about the risks and rewards of this new choice, but critics argue that frontier in food production and agriculture. consumers are not sufficiently informed to make rational choices. What are GM foods? R BEET PAPAYA Genetically modified foods are crops that have SUGA CORN had specific genes altered or manipulated using TON techniques of genetic engineering. Traditional SOY COT breeding mixes hundreds or thousands of genes at a time, but this happens over the GM foods course of generations. New technologies make Eight types of GM foods are commercially available— it possible to target single genes and to transfer corn, soybeans, cotton (for oil), canola (also a source genes from one species to another unrelated of oil), squash, papaya, sugar beets (for sugar), and organism, for instance, from bacterium to plant. Such changes cannot be achieved alfalfa (for animal feed). by conventional plant breeding. Insecticide-producing Gene switched off genes from bacteria TOMATO Inserting genes inserted into corn Suppressing genes A desirable gene from one species is Alternatively, organisms can be modified by transplanted to a new switching off genes species. Insecticide- producing genes from so they don’t express themselves. Some Bacillus thuringiensis fruits, such as have been inserted into the DNA of corn tomatoes, have softening genes to produce a crop turned off so they that makes its own BACILLUS GENE GENE GENE insecticide. THURINGIENSIS CODE CODE CORN will last longer. This CODE method is less common. Why are they made? CONTROL PESTS MANAGE CROP DISEASE MANAGE WEEDS CHANGE NUTRITION GM foods are made so that more crops are resistant to pests and disease, and therefore survive to provide higher yields. Herbicide- resistant crops allow farmers to use herbicide more efficiently to kill weeds, and crops can even be genetically modified to enhance nutrition.
242 243FOOD AND ENVIRONMENT Genetically modified foods The GM debate Despite the flourishing culture of anti-GM food opinion and activism, there are no well-supported or scientifically respectable large-scale studies to support claims that GM foods pose a risk to human health. The rational counterargument ARGUMENTS FOR GM is that GM foods comprise a colossal public Good or bad? Supporters argue that there health experiment without informed are real and potential benefits to GM foods, but there are consent and with unknown long-term biological, environmental, and economic concerns to consider. outcomes. The spread of new, Here are just some of the arguments for and against. altered genes into wild populations ARGUMENTS AGAINST GM also has unknown effects on Risk of disease the environment. Meanwhile, Options for vegans Some GM crops are the food industry has moved Plants could contain meat monocultures (genetically on without waiting for the and dairy components identical) and this genetic debate to settle—GM foods (such as vitamin B12) if they similarity means they all may are commonplace in had the genes for them. be equally vulnerable to the countries such as the US. same infectious disease. This could open up new dietary possibilities for vegans. Fewer chemicals Pest-resistant, fast-growing GM crops mean there is a reduced need for pesticides and fertilizers, which benefits the environment (see pp.230–31). Global demand More chemicals Modifying crops that are If GM crops are bred to adapted for difficult and be resistant to weed-killer changing conditions, chemicals (herbicides), farmers with enhanced nutrition, are free to use more herbicide, will be necessary to which can kill natural plants living around the farm and meet the demands cause wide environmental and changing needs damage downstream. of a growing population. Corporate power 90 PERCENT GM foods are produced OF SOY, CORN, using genetically modified COTTON, CANOLA, organisms (GMOs), and are AND SUGAR BEETS generally patented and have to SOLD IN THE US HAVE be bought anew each growing BEEN GENETICALLY season. They are controlled by a ENGINEERED handful of major multinationals.
Overfishing and sustainable fishing Fish are more popular than ever, partly due to the increasing awareness of their health benefits. But the world’s insatiable appetite has almost drained the once apparently limitless resources of the ocean—often with catastrophic results to ecosystems. Fish farming and sustainable fishing may provide solutions to these problems. Global hunger for fish IS IT OK TO EAT TUNA? Around three billion people in the world, in order to obtain enough protein, rely on either wild-caught or farmed seafood, including The once-abundant bluefin fish. On average, each person eats four times as much seafood now tuna is now critically endangered, than they did in 1950. To satisfy this great demand, global fisheries have already been pushed past their limits. When fish stocks and many other tuna species (populations) fall steadily, they are being overfished—and this is are decimated. They are large unsustainable because these fish will, sooner or later, become too predators, and so like big cats or scarce to support a fishery—or worse, become extinct entirely. birds of prey, they are naturally The United Nations Food and Agriculture Organization (UNFAO) scarce—so we can’t eat them says we will need another 40 million tons (36.3 million metric tons) of seafood worldwide per year by 2030 just to meet current too much or too fast. consumption rates, based on current population projections. A rise in fishing Since the 1950s, global fishing of wild populations (wild fisheries) has been rapidly increasing, along with aquaculture (fish farming). By the 1990s, fishing plateaued as fish stocks became depleted. In response, fish farming grew even more rapidly—and continues to grow. KEY Fish farming Wild fisheries 84 PERCENT OF FISH STOCKS ARE EITHER FULLY EXPLOITED OR OVERFISHED YEAR 1960 1970 1950
244 245FOOD AND ENVIRONMENT Overfishing and sustainable fishing How to fish sustainably NO-CATCH AREAS NO BOTTOM TRAWLING PREVENTING FRAUD 160 REDUCE BYCATCH SUBSTITUTION OF STOCKS 140 Sustainable fishing preserves fish 120 populations and allows them to LINE-AND-POLE Are fish farms the solution? 100 replenish themselves. It involves a Fish farming involves raising fish and other mixture of good practice, such as: seafood in captivity, usually in giant ponds no-catch areas, where fishing is or netted enclosures. Whether fish farming illegal; no bottom-trawling, to is sustainable or not depends on whether avoid damaging fragile ecosystems the fishmeal they are fed was sustainably such as reefs; preventing fraud, in fished itself. which fishers misreport catches; reducing bycatch by using nets that allow fry and other accidentally caught species to escape; buying other species of fish that are not overfished; and fishing using a line and pole, which targets individual fish rather than entire schools. FISH LANDINGS IN THOUSAND TONS 80 GLOBAL FISH LANDINGS IN MILLION TONS COLLAPSE OF ATLANTIC COD STOCK One of the most dramatic instances 725 Factory ships Canada 60 of a fishery collapse was the Grand 540 cause spike in suspends 40 Banks cod fishery off Newfoundland. 360 cod fishing Cod were once so plentiful in the 180 cod catches in the area that it was possible to scoop region in them out of the sea with a basket. 0 1992 The implementation of factory ships 1900 in the 1960s caused a massive spike 20 in catches, but they quickly declined and fell completely in the 1990s. 1925 1950 1975 2000 Recovery is slow because cod fry are YEAR quickly eaten by predators. Adult cod would normally eat the predators of the fry, but since they are absent very few cod ever grow up. 1990 2000 2010
Future foods The technology behind food production and 2 Sun’s energy agriculture continues to improve, bringing Surface seawater about more efficient, sustainable ways to runs through pipes along produce food—on both large and local scales. the greenhouse roof where it is heated by the sun. Solar panels harvest sunlight to generate the electricity to power the fans and pumps Farms of the future that move the seawater. Tomorrow’s farms will have to feed a rapidly growing population that will demand more and better food. They will also have to cope with climate change, soil degradation, water shortages, non-native pests, and new diseases. To overcome these challenges and meet 3 Air humidified The hot seawater these needs, innovative solutions are already being explored, by retooling the agricultural wisdom of ancient cultures, runs down another porous wall. The cool, or by creating entirely new, controlled systems. moist air is drawn Seawater Seawater greenhouses heated by sun through this wall, and For hot, arid seaside regions where crops as it passes through it is are unable to grow, seawater greenhouses Seawater heated and can pick up produce a hospitable growing climate trickles down even more moisture. and create freshwater with absorbent wall which to irrigate crops. Cool, moist air creates Hot seawater favorable growing conditions drips down Dust MOISTURE Hot air saturated with moisture HOT, DUSTY AIR COOL, MOIST AIR FAN CONDENSER 1 Using seawater Freshwater irrigates crops CROPS Surface seawater is pumped and cascaded down a Freshwater condenses porous, absorbent cardboard wall. Hot air from outside is drawn through the wall by airflow created by fans—it is cooled and saturated with moisture as it passes through the wet wall. Seawater drains back to the sea FRESHWATER STORAGE SURFACE 5 Irrigation 4 Freshwater condenses SEAWATER The freshwater is used to irrigate Deep, cool seawater is pumped DEEP SEAWATER the crops in the greenhouse, and also any additional crops in the surrounding through a series of vertical pipes into SEAWATER DRAINAGE the condenser. When the hot, humid air area. A wide range of produce can be from the greenhouse meets these pipes, grown, as in a traditional greenhouse, including tomatoes, cucumbers, peppers, freshwater condenses onto the surfaces of the pipes, which then collects in a storage lettuce, strawberries, and herbs. The tank. The salt from the seawater can be whole process is controlled by computer. collected as a useful byproduct.
246 247FOOD AND ENVIRONMENT Future foods New sources of meat GREENHOUSES ON MARS The growing demand for meat around the world— Martian soil contains most of the nutrients and the inefficiency with which some countries needed to grow plants, but there is almost no raise their livestock (see pp.228–29)—means atmosphere on Mars, freezing temperatures, there is an urgent need for alternatives. Insects no running water, and damaging radiation. are already eaten by many (see p.148) and could Greenhouses have been proposed that might be a more sustainable source of meat. Not only is be able to concentrate the sun and trap gases 80 percent of a cricket’s body edible, compared to to create growing conditions. only 40 percent of a cow’s, there is actually more protein in 31⁄2oz (100g) of cricket than in beef. 80 percent 40 edible percent edible CRICKET COW Reimagining ideas PLANTS Natural fertilizer Medieval Aztecs used to raise crops without soil whilst Microbes and composting worms suspending them above lakes. Today, aquaponics does feed on the fish waste and turn something similar. It is an agricultural system that it into a natural fertilizer for combines fish farming and growing plants without soil. the suspended plants. It functions independently—and therefore could be a more sustainable way to farm fish and raise crops. SCIENTISTS IN JAPAN ARE WORKING ON A KITCHEN THAT PROJECTS PREPARATION INSTRUCTIONS ONTO FOOD FISH WASTE FISH Food source Cleansing The waste the fish produce Plants are grown in the same provides a food source water as the fish. They for microbes and filter the water, which helps composting worms. keep the fish healthy.
Index ale 173 in soy sauce 103 battle butties 58 alfalfa 242 in tea 157, 184 beans 100–01, 106, 126, 229 Page numbers in bold refer algae 81, 149 in vegetarian diets 189 beef 26, 65, 68, 72–73, 81, 101, 113, to main entries. algal blooms 230 aphids 231 alkaline diet 204–05 aphrodisiacs 80 189, 229, 247 5:2 diet 200–01 alkaloids 55, 111 appetite 14–15 beer 165, 166, 172–73 allergies 206–07, 210 apples 122, 158 beets 109, 117, 135 A allicin 118 fiber 24 beige fat 191 alliin 119 freshness 46–47 berry fruits 123 acai berries 109 alliums 118 seeds 122 best before 47 acetaldehyde 166, 167, 168 almonds 108, 109, 126 vitamins 41 beta-carotene 107, 116, 120 acidity regulators 59 alpha-linolenic acid (ALA) 78 APT 23 bifidobacteria 87 acrylamide 95 alternate day diet 200–201 aquaponics 247 bile 20, 21, 25, 30, 31 additives 58–59 alternative foods 148–49 arabica coffee 154 binge eating 224, 225 Alzheimer’s disease 193 aromatic oils 130 bioavailability 115 alcohol 169 amaranth 92, 93, 109 arsenic 223 bioreactors 149 animal fodder 232 amino acids 13, 26–27, 63, 69, 103, arteries biotechnologies 228 carbonated drinks 160 and blood pressure 213 birds 148 convenience foods 39 162, 163, 190, 191 and cholesterol 31, 214, 215 birth defects 221 and intolerances 208 intolerance to 208 Asian cuisine 184 bitter taste 17, 19 processed foods 57 ammonia 76, 77, 100, 101 aspartame 16, 138 black tea 156, 157 tap water 152 amylopectin 90, 91, 104 Aspergillus flavus 125 blending 159 unwanted 236 amylose 90, 91, 93 asthma 182, 206 blindness 42 whole foods 40 anemia 12, 33, 35, 167, 218, 219 astringency 17 bloating 208, 209 adenosine 163 anaerobic exercise 192 atheroma 215 blood adipose tissue 15 anaphylaxis 206, 207 Australian diet 139, 177 adrenaline 27, 163, 207 anatomy, evolution 8 autoinjectors 207 alcohol in 168, 169 aerobic exercise 192 anethole 130 avocados 108, 109, 121, 208 water in 36 aflatoxins 125 animals blood clots 31, 118, 215 agriculture 228, 246 fasting 201 B blood glucose levels 91 factory farming or free-range rearing conditions 232–33 blood pressure welfare 187, 188, 233 babies 222 diet and 212–13 232–33 anorexia 224–25 Bacillus cereus 65 exercise and 193 fair trade 234–35 anthocyanins 106, 123, 170 Bacillus Thuringiensis 242 garlic and 118 food waste 238, 239 anti-caking agents 59, 134 bacteria high 31, 134, 135, 155, 163, GM foods 242–43 anti-inflammatories 115, 133, 184 history 9 antimicrobials 48, 74, 184 antibiotic resistant 233 212–13, 214 intensive 228, 230–31, 241 antibiotics 87, 206, 208 and cooking 64, 65 low 36, 159, 196, 201 organic 230, 231 for livestock 231, 232, 233 fermenting 86–87, 144 blood sugar levels 14, 23, 91, 101, air freight 46 antibodies 33, 99, 206–07 and freezing 50 140–41, 162, 216, 217, 221 airplane food 19 antihistamines 207 and freshness 47 blood vessels 118, 159, 168, 215, alcohol 164–65 antioxidants 32, 33, 35, 40, 111 in gut 25, 189, 199 216 abuse 167 additives 58, 160 and immune system 206 blood-type diet 204–05 beer 172–73 in alcohol 165, 170, 171, 172 pasteurization 56, 84 blueberries 108, 109 and the body 164, 168–69, 212, in cocoa 145 starter cultures 95 BMI (body mass index) 68, 190 in eggs 82 vitamin production 25 BMR (basal metabolic rate) 192–93 215 in fruit and vegetables 104, 106, baking 60, 95 body and cancer 219 baking powder 142 alcohol and the 164, 168–69, 212, fermentation 52 107, 108, 109, 112, 113, 115, 118, baking soda 94, 135, 142, 147 in pregnancy 221 121, 122, 123 balanced diet 12, 13, 176–77, 194 215 prohibition of 186, 187 and heart disease 215 bananas 51, 91, 122, 125 fats in the 29 spirits 166–67 in herbs 133 fair trade 234–35 nutrition 12–13 wine 170–71 instability of 48 barn-raised 233 see also health yeast and 125 in raw food 54 basil 133 body dysmorphic disorder 224 alcohol by volume (ABV) 166 in smoked food 48, 74 boiling 60 alcoholism 169 bones exercise and 193
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