Energy Nutrients in Brief

Energy Containing Nutrients in Brief 1

Food is Your Fuel…What are You Running On?

What is in our food?• Carbohydrates – 4 calories per gram• Protein – 4 calories per gram• Fat – 9 calories per gram• Alcohol – 7 calories per gram

Healthy Diet: Caloric breakdown PROTEIN 10-15% FAT CHO 20-35% 45-65%

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What are carbohydrates?• Carbohydrates, together with lipids, proteins and nucleic acids, are one of the four major classes of biologically essential organic molecules found in all living organisms.• Carbohydrates, all coming from the process of photosynthesis, are the most abundant organic components in the major part of fruits, vegetables, legumes and cereal grains, carry out many functions in all living organisms. 6

PLANTS are the major source of carbohydrates in the food we eat 7

Types: Simple Carbohydrates• Glucose, fructose, and galactose (Monosaccharides)• Lactose (milk sugar), maltose, and sucrose (Disaccharides)• Examples: – Sugar, corn sweetener, syrup, honey – Sodas, candy, bakery and processed goods • Easily broken down • Provides quick energy • Excess converted to fat for storage 8

Types: Complex Carbohydrates• Starch, glycogen, most fibers• Examples:– 1 slice whole-grain bread– 1 cup whole grain cereal– ½ cup cooked pasta or rice• Broken down more slowly– More fiber - Broken down slowly = fuller longer= longer satiated• Majority of carbohydrates in the diet should becomplex 9

Summary of dietary fiber classes Source FunctionCellulose Main cell wall Holds water; reduces elevated constituent of plants colonic intraluminal pressure; binds zincHemicellulose Cell wall plant material Holds water and increases stool bulk; reduces elevated colonic pressure; binds bile acidsLignin Woody part of plants Antioxidant; binds bile acids, cholesterol, and metalsNoncellulose polysaccharidesGums Secretions of plants Slows gastric emptying;Mucilages Plants secretions and provides fermentable material forAlgal seeds colonic bacteria with productionpolysaccharides of gas and volatile fatty acids; Algae, seaweeds binds bile acids and cholesterolPectin substances Intercellular cement plant 10 material

Functions• Primary source of energy and regulation of blood glucose (4 Cal/gram)• Sparing the use of proteins for energy• Breakdown of fatty acids and preventing ketosis• Promote Digestive Health• Flavor and Sweeteners 11

Requirements• Recommended intake: 45-65% of total calories from carbohydrates• Added sugars not more than 25% of total calories intake• Dietary fiber 25 gram a day• To prevent ketosis, an intake of 100 grams of carbohydrates per day is suggested 12

LIPIDS

Good things about lipids

Bad things about lipids

Xanthelasmas XanthomaCorneal Arcus Achille’s tendon thickening

What are lipids?Lipids are naturally occurringhydrophobic molecules. They areheterogenous group of compoundsrelated to fatty acids. They include fats,oils, waxes, phospholipids, sterols.Fatty Acids—Basic building blocks for fats

Types: Saturated fats BAD FATS• Solid at room temperature• Negative effects on heart health• Primarily found in animal fats – White, visible fat found in meats – Dairy products: whole milk, butter, cream, hard cheeses• Also found in Coconut and palm oils

Types of dietary fats: Unsaturated fats GOOD FATS Monounsaturated and polyunsaturated fats• Liquid at room temperature• Positive effects on heart health• Primarily from vegetable sources: – Olive and canola oil – Nuts/nut butters – Avocado• Also found in fish oils• Omega-3 polyunsaturated fats found in fish are considered especially healthful

Types: Trans Fats• fats that result when liquid oil has hydrogen added to it to make it more solid.• Altered form of unsaturated fat (hydrogen added)• Associated with unhealthy changes in cell membranes• Raises levels of “bad” cholesterol and lowers levels of “good” cholesterol• Found in margarine, snack foods, and some deep fried fast foods

Composition of Dietary Fats

Types: Cholesterol• White fatlike substance found in cells of animal origin• Functions: Synthesizes cell membranes; starting material in formation of hormones and bile• The liver can synthesize cholesterol• Excess cholesterol in the body can clog arteries and increase risk of cardiovascular disease

Functions• Reserve energy of the body (9 calories/gram)• Component of cell membrane structure, myelination• Source for fat soluble vitamins like A, D, E, K.• Some lipids like prostaglandins and steroid hormones act as cellular metabolic regulators.• Act as signal transmission• Hormone synthesis• Bile acid synthesis• Essential fatty acids are precursors of many different types of ecosanoids that play a important role in pain, fever, inflammation and blood clotting. http://biology.tutorvista.com/biomolecules/lipids.html

Requirements• 20-35% of total daily energy from fat• Linoleic acid: 5−10% of energy• Alpha-linolenic acid: 0.6−1.2% of energy• Saturated fat: less than 10% of energy• Cholesterol: less than 300 mg/day• Trans fat: less than 1% of energy or as low as possible• Get most fats from sources of unsaturated fats: fish, nuts, vegetable oils





• Proteins are large, complex molecules that play many critical roles in the body. They do most of the work in cells and are required for the structure, function, and regulation of the body’s tissues and organs.• Proteins are made up of hundreds or thousands of smaller units called amino acids, which are attached to one another in long chains. There are 20 different types of amino acids that can be combined to make a protein

• Amino acids = building blocks of protein – 11 can be built by the body • Nonessential amino acids – 9 must be obtained from food • Essential amino acids• Found in: – meats, poultry, and fish – beans and peas – tofu – eggs – nuts and seeds – milk & dairy products

• The value of dietary proteins depends on their composition of essential amino acids. Our body need all nine essential amino acids from foods for protein synthesis. IF – Limiting amino acid • Essential amino acid that is missing or in the smallest supply • Slows down or halts protein synthesis – Inadequate energy consumption • Limits protein synthesis

• Complete protein (high quality): sufficient amounts of all nine essential amino acids – Derived from animal and soy protein• Incomplete protein (low quality): insufficient essential amino acids – Does not support growth and health – Derived from plant sources• Complementary proteins: two or more foods are combined to supply all nine essential amino acids for a complete protein



• Humans cannot store excess amino acids not used for protein synthesis; they must be degraded and the N eliminated in the urine• In adults, dietary N requirements are determined by the need to replace obligatory losses• Once the true requirement is met, the N balance will tend to remain close to zero



• Is primarily used to build, maintain and repair body tissues• Formation of antibodies to strengthen immune system• Foundation of hormones, enzymes, and blood cells• Regulate fluid balance• Help carry substances throughout the body• Maintain acid-base balance• Providing energy (4 Calories/gram, will be used only after other energy sources are unavailable )

• Recommended intake: 10-15% of total calories• Guidelines – Choose leaner meats – Get hooked on fish! Eat fish twice a week for a great source of protein! – Include protein at every meal to curb feelings of hunger