Lecture 3 Nutrition, Part 1 1 Nutrition 1.Macronutrients a. Water b. Carbohydrates c. Proteins d. Fats 2.Micronutrients a. Minerals b. Vitamins 2 1
Why is Nutrition Important? Your food choices each day affect your health how you feel today, tomorrow, and in the future. Nutrient a substance that provides nourishment essential for growth and the maintenance of life. 2
Types of Nutrients Essential Nutrients - needed to build, maintain, and repair tissues and regulate body functions 1. Macronutrients - needed in large amounts: Water! 6 3
2. Micronutrients - needed in small amounts Vitamins, minerals 7 Water -The Unappreciated Nutrient Function: Digests, absorbs, transports nutrients Helps regulate body temperature Carries waste out of the body Lubricates our body parts Fluid Balance - right amount of fluid inside and outside each cell; maintained by electrolytes 8 4
Water - The Unappreciated Nutrient In most places in U.S. tap water is of equal or superior quality to bottled water RDA: 1 to 1.5 milliliters per calorie spent 2 to 3 liters, or 8 to 12 cups of fluid Water needs can vary depending on several factors, such as foods consumed and activity level 9 Macronutrients: Carbohydrates 10 5
Carbohydrates - The Body s Fuel The body s main source of energy Fuel most of the body s cells during daily activities Used by muscle cells during high-intensity exercise Only source of energy for brain cells, red-blood cells, and some other types of cells 11 Carbohydrates - The Body s Fuel RDA: 130 grams for males and females (aged 1 70) 12 6
Carbohydrates - The Body s Fuel Types: Simple Carbohydrates (sugars) Complex Carbohydrates (starches and dietary fibers) 13 Simple Carbohydrates Simple Carbohydrates: Easily digestible and composed of one or two units of sugar Glucose, fructose, galactose, lactose, maltose, sucrose, etc. 14 7
15 Simple Carbohydrates Too many simple carbohydrates leaves you with a sugar high, followed by a feeling of depletion, and a craving for more sugar Added sugars have even more dramatic effect High fructose corn syrup (HFCS) 16 8
Simple Carbohydrates Too many simple carbohydrates leaves you with a sugar high, followed by a feeling of depletion, and a craving for more sugar Added sugars have even more dramatic effect High fructose corn syrup (HFCS) 17 Complex Carbohydrates Complex Carbohydrates: Composed of multiple sugar units including starches and dietary fiber 18 9
Complex Carbohydrates Complex Carbohydrates: Sources: Whole grains (whole wheat, brown rice, oatmeal, corn) Vegetables; some fruit 19 Complex Carbohydrates Complex Carbohydrates: Whole grains preferred over refined carbohydrates (white flour products) Provide more nutrients, Slow digestive process Make you feel full longer 20 10
21 Fiber Dietary Fiber - complex carbohydrate found in plants that cannot be broken down by the digestive tract Fiber allows for passage of food quickly through the large intestine which helps prevent hemorrhoids and constipation Curbs your appetite Give the feeling of being full 22 11
Fiber Soluble Fiber - dissolves in water and lowers cholesterol 23 Fiber Insoluble Fiber - passes through digestive tract unchanged; serves as natural laxative 24 12
Fiber RDA: 25 grams/day for women (aged 19-50) 38 grams/day for men (aged 14-50) Fiber is best obtained through diet, not pills or supplements Sources of fiber: Fruits & Vegetables Dried beans Peas and other legumes Cereals & Grains Nuts & Seeds 25 26 13
Macronutrients: Proteins 27 Protein Main Function: Build and maintain muscles, bones, and other body tissues 28 14
Protein What are they made of: Constructed from 20 different amino acids Your body can make 11 of the 20 amino acids 9 Essential Amino Acids (EAAs), can t be made by the body, must be supplied by foods 29 Protein Amino Acids 30 15
Protein Protein Sources: 1. Complete Proteins (get all EAAs) 2. Incomplete Proteins (don t get all EAAs) 31 Protein Complete Protein Sources provide all essential amino acids Animal proteins: meat, fish, poultry, milk, cheese, eggs 32 16
Protein Incomplete Protein Sources do not provide all essential amino acids Vegetable proteins: grains, legumes, nuts, seeds, other vegetables 33 Protein Complementary Proteins - proteins that in combination provide essential amino acids e.g. beans and rice Mutual Supplementation - nutritional strategy of combining two incomplete protein sources to provide a complete protein 17
Protein RDA: 0.36 grams per pound of body weight 35 Macronutrients: Fats (Lipids) 36 18
Fats - A Necessary Nutrient Principal form of stored energy in the body Provide emergency reserve when we are sick or when our food intake is diminished RDA: 20-35% of calories from fat with only about one-third coming from saturated fats 37 Why are fats good for energy storage? kcal (calorie) = measure of stored energy 38 19
Fats - A Necessary Nutrient In general, macronutrients that are not used following ingestion are converted and stored as fat 39 Fats - A Necessary Nutrient Fats do other things too: Essential fatty acids Production of Vitamin D Cell Membranes Affect texture, taste, and smell of foods 40 20
Types of Fat Saturated Fat - found in animal products and other fats that remain solid at room temperature Beef Pork Poultry Whole-milk dairy products 41 Types of Fat Monounsaturated Fat - found primarily in plant sources, are liquid at room temperature, and are semisolid or solid when refrigerated Olive, safflower, peanut and canola oils Avocados Many nuts 21
Types of Fat Polyunsaturated Fat - commonly referred to as oil ; liquid at room temperature and when refrigerated Corn and soybean oils Fish, including trout, salmon, and anchovies 43 Cholesterol A waxy substance that is needed for several important body functions The body produces it from the liver and obtains it from animal food sources (meat, cheese, eggs, milk) 44 22
Cholesterol LDLs (low density lipoproteins) are the bad cholesterol, sticky, clogs arteries HDLs (high density lipoproteins) are considered good Recommended: consume no more than 300 milligrams per day 45 Cholesterol Too much LDLs can clog arteries and lead to cardiovascular disease, but not all cholesterol is bad 46 23
Cholesterol 47 Cholesterol 48 24
Trans Fats Liquid vegetable oils that have been chemically changed through the process of hydrogenation to extend the shelf life of processed foods Pose a risk to cardiovascular health by raising LDL levels and lowering HDL levels 49 Trans Fats Foods high in trans fatty acids include: Crackers, cookies, chips Cakes and pies Doughnuts Deep fried foods like French fries 50 25
Micronutrients: Minerals 51 Minerals Minerals are naturally occurring substances needed by the body in small amounts Build strong bones and teeth, and help carry out metabolic processes and body functions 52 26
Minerals The body needs 20 essential minerals Macrominerals (need at least 100 mgs/day) Calcium, chloride, magnesium, phosphorous, potassium, sodium 53 Minerals - A Need for Balance The body needs 20 essential minerals Microminerals (need less than 100 mgs/day) Chromium, cobalt, copper, fluorine, iodine, iron, zinc, manganese, nickel, and others A balanced diet provides all the essential minerals the body needs per day 54 27
Minerals e.g. Iron (Fe) Hemoglobin 55 Minerals - A Need for Balance 56 28
Minerals Not enough Iron Anemia 57 Minerals - A Need for Balance 58 29
Micronutrients: Vitamins 59 Vitamins - Small But Potent Nutrients Naturally occurring organic substances needed by the body in small amounts Water-Soluble vs. Fat-Soluble Vitamins Your body needs at least 11 specific vitamins A, C, D, E, K, and the B-complex vitamins Vitamins can be found in a variety of foods, so often supplements are unnecessary 60 30
Vitamin D 61 Vitamin D 62 31
Key Vitamins and Minerals 63 Other Substances in Food: Phytochemicals Phytochemicals: substances naturally produced by plants May keep cells healthy, slow tissue degeneration, prevent carcinogens, reduce cholesterol, protect heart, maintain hormone levels, keep bones strong 64 32
Phytochemicals - Antioxidants 65 Other Substances in Food: Phytochemicals Three important types of phytochemicals: Antioxidants - neutralize free radicals Phytoestrogens - lower cholesterol and reduce risk of heart disease Phytonutraceuticals - may inhibit growth of cancer and heart disease 66 33
Phytochemicals 67 The Color Wheel of Foods What Color Is Your Diet? D. Heber 68 34