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Chapter 3 NUTRITION FOR WELLNESS Objectives Define nutrition and describe its relationship to health and wellbeing. Learn to use the USDA MyPlate guidelines for healthier eating. Describe the functions of the nutrients – carbohydrates, fiber, fats, proteins, vitamins, minerals, and water – in the human body. Define the various energy production mechanisms of the human body. Be able to conduct a comprehensive nutrient analysis and implement changes to meet the Dietary Reference Intakes (DRIs). Identify myths and fallacies regarding nutrition. Become aware of guidelines for nutrient supplementation. Learn the 2010 Dietary Guidelines for Americans. Eat this or that? Introduction Proper nutrition is essential to overall health Having good nutrition: Means that a person's diet supplies the essential nutrients needed to carry out normal tissue growth and repair. Supplies enough substrates to fuel all body processes. The USDA provides nutrition guidelines and recommended daily food amounts according to various caloric requirements. Introduction Nutrients should be obtained from a wide variety of sources. U.S. diet Too high in calories, sugar, saturated fat, trans fat, sodium Too low in grains, fruits, vegetables Diet and nutrition play a role in the development and progression of heart disease, cancer, obesity, diabetes, and osteoporosis Nutrients Six essential nutrients By function: Fuel Nutrients needed for energy: carbohydrates, fats, and proteins. Regulatory nutrients necessary to function normally with no caloric value: vitamins, minerals, water, and fiber. By Amount: Macronutrients needed in proportionally large amounts daily: carbohydrates, fats, proteins, and water. Micronutrients required in small amounts daily: vitamins and minerals. Nutrients Nutrient Density Foods packed with nutrients but with low or moderate calories are classified as having high nutrient density. Calorie: The simplified term for a kilocalorie (kcal), the amount of heat necessary to raise the temperature of 1 kilogram of water 1 degree Centigrade. MyPlate food plan MyPlate food groups Vegetables are divided into 5 subgroups Dark green vegetables 2. Red and orange vegetables 3. Beans and peas 4. Starchy vegetables 5. Other vegetables Fruits Grains are divided into 2 subgroups Whole grains Refined grains 1. Protein Includes meat, poultry, seafood, beans and peas, eggs, soy products, nuts and seeds Dairy Choose low-fat or fat-free options Cream cheese, cream and butter are not part of the dairy group Recommended daily amounts of nutrients Carbohydrates Major source of energy (4 calories/gram) Regulate fat and metabolize protein Major sources are breads, cereals, fruits, vegetables, milk/dairy products Two types: Simple Complex Major Types of Carbohydrates Simple Carbohydrates Often called “sugars,” which have little nutritive value Examples are candy, soda, and cakes Divided into monosaccharides and disaccharides Monosaccharides: glucose, fructose, galactose Disaccharides: sucrose, lactose, maltose Complex Carbohydrates Also referred to as “polysaccharides” Carbohydrates formed by ten or more monosaccharide molecules linked together Starches Dextrins Storage form of glucose in plants Formed from the breakdown of starches exposed to dry heat Glycogen Storage form of glucose Fiber Form of complex carbohydrates Present mainly in plant leaves, skins, roots, and seeds Processing and refining foods removes most of their natural fiber Dietary sources include Whole-grain cereals and breads Fruits and vegetables Legumes Fiber Soluble fiber Insoluble fiber Dissolves in water to form gel-like substance that encloses food particles Helps decrease blood cholesterol and blood sugar levels Oats, fruits, barley, legumes, psyllium Not easily dissolved in water but binds with water Causes a softer and bulkier stool Speeds passage of food residues through intestines Wheat, cereals, vegetables, skins of fruits Most common types of fiber are: 1. 2. 3. 4. Cellulose – found in plant cell walls Hemicellulose – found in cereal fibers Pectins – found in vegetables and fruits Gums and mucilages – found in small amount of food of plant origin High-fiber foods are essential in a healthy diet Age 50 and under Over age 50 Women = 25 g/day Men = 38 g/day Women = 21 g/day Men = 30 g/day Current average daily U.S. intake About 15 g/day Fat Also called lipids Most concentrated source of energy (9 cal/gram) Need fat for: Part of cell structure Stored energy Insulator for body heat preservation Shock absorption Supplies essential fatty acids Carries fat-soluble vitamins (A, D, E, K) Major types of fats (lipids) Simple Fats Over 90% of the weight of fat in foods and over 95% of the fat stored in the body are in the form of triglycerides Saturated fats are mainly of animal origin Unsaturated are found mostly in plant products Further classified into monounsaturated and polyunsaturated fatty acids Chemical structure of saturated and unsaturated fats Saturated Fats Meats, animal fat, lard, whole milk, cream, butter, cheese, ice cream, hydrogenated oils, coconut oil, and palm oils Usually do not melt at room temperature Coconut oil and palm oils are exceptions Raise blood cholesterol level Unsaturated Fats Usually liquid at room temperature Help lower blood cholesterol Monounsaturated fats (MUFAS) found in olive, canola, peanut, sesame oils, avocados, cashews, and peanuts Polyunsaturated fats (PUFAS) found in corn, cottonseed, safflower, walnut, sunflower, soybean oils, and fish, almonds, pecans Fats (Lipids) Trans fatty acids The result of partial hydrogenation to increase shelf life. Provide no known health benefit. The words "partially hydrogenated" and "trans fatty acids" indicate that the product carries a health risk just as high as or higher than that of saturated fat. Found in Margarine and spreads, shortening, some nut butters, crackers, cookies, dairy products, meats, processed foods, and fast foods Fats (Lipids) Polyunsaturated omega fatty acids Essential to human health and have to be consumed in the diet. Omega-3 fatty acids Polyunsaturated fatty acids found primarily in cold-water seafood and flaxseeds thought to lower blood cholesterol and triglycerides Three major types of omega-3 fatty acids: EPA, DHA, and ALA protect against irregular heartbeats and blood clots, reduce triglycerides and blood pressure, and defend against inflammation. Omega-6 fatty acids LA, GLA, and AA Excessive intake tends to contribute to inflammation – 4 to 1 ratio recommended Fats (Lipids) The canning process for fish destroys most of the omega-3 fatty acids Good sources of omega-3 ALA include flaxseeds, canola oil, walnuts, wheat germ, and green leafy vegetables Fats (Lipids) Compound fats Lipoproteins transport fats in the blood and play a large role in heart disease Major forms are HDL, LDL, VLDL Derived fats Sterols Found in food and manufactured in the body primarily from saturated and trans fats Proteins Needed for: Build and repair tissue Part of hormones, antibodies, and enzymes Necessary for normal functioning Help maintain normal body fluid balance Source of energy (4 calories/gram) if carbohydrate is insufficient Sources are meats and alternatives, milk, and other dairy products Excess proteins can be converted to glucose or fat, or excreted in urine Daily consumption of beef, poultry, or fish should be limited to 3 ounces to 6 ounces. Amino Acids The body uses 20 amino acids to form different types of protein 9 amino acids are termed “essential” because the body cannot produce them 11 amino acids are termed “nonessential” because the body can produce them if food proteins in the diet provide adequate nitrogen All amino acids must be present in the diet for the body to function normally Vitamins Organic nutrients essential for normal metabolism, growth, and development Classified according to solubility Fat soluble (A, D, E, and K) Water soluble (B complex and C) Most vitamins must be obtained through diet A, D, and K are formed in the body C, E, and beta-carotene are “antioxidants” Minerals Inorganic nutrients essential for normal body functions Part of all cells Help maintain water balance and acid-base balance Essential components of enzymes Regulate muscular and nervous tissue impulses, blood clotting, normal heart rhythms Water Most important nutrient Studies show people are getting enough water from the liquids and the moisture content of solid foods. To avoid dehydration, use the thirst signal Exception is exercise Balancing the American Diet National Academy of Sciences created guidelines for a wellbalanced diet The ranges allow for flexibility in planning diets for individual health and physical activity needs The source of fat calories is critical Dietary Reference Intakes describe nutrition standards 1. Estimated Age Requirement (EAR) Amount of nutrient meeting the dietary need for half the people in a specific age and gender group 2. Recommended Dietary Allowance (RDA) Daily amount of a nutrient considered adequate to meet known nutrient needs of almost 98% of all healthy people in the United States 3. Adequate Intake (AI) Recommended amount of intake when EAR and RDA aren’t available 4. Tolerable Upper Intake Level (UL) Highest level of nutrient intake that seems safe for most healthy people, beyond which exists an increased risk of adverse effects Nutrition Standards Daily Values Reference values for nutrients and food components listed on food-packaging labels Based on a 2,000 calorie/day diet Need to be adjusted based on an individual’s Estimated Energy Requirement Average dietary energy intake predicted to maintain energy balance in a healthy adult of a defined age, gender, weight, height and level of physical activity, consistent with good health Food Label with U.S. Recommended Daily Values Nutrient Analysis Keep a 3-day record of all foods and beverages consumed Includes measurements of calories, carbohydrates, fats, protein, cholesterol, sodium, vitamins, and minerals. Use the food tracker on choosemyplate.gov Nutrient Analysis Most revealing information learned in a nutrient analysis is the source of fat intake Average daily fat consumption in the U.S. diet About 34% of the total caloric intake Much of it from saturated fat and trans fatty acids, which increase the risk for chronic diseases Achieving a balanced diet Vegetables, fruits whole grains and dairy provide base for healthy diet Vegetables and fruits are the sole source of Phytonutrients which prevent and fight cancer • When increasing nutrients from above food groups, reduce the intake of low-nutrient foods Choosing Healthy Foods Learn the nutritive value of typical foods you eat by reading food labels Be aware that there is label misinformation as the FDA does not have the manpower to regularly check food labels Healthy eating requires proper meal planning and adequate coping strategies Choosing Healthy Foods Vegetarianism Diet consisting of foods with vegetable or plant origin Five types of vegetarians 1. Vegans – eat no animal products 2. Ovovegetarians – allow eggs in their diet 3. Lactovegetarians – consume foods from the milk group 4. Ovolactovegetarians – include egg and milk products in their diet 5. Semivegetarians – do not eat red meat, but eat fish and poultry, milk products and eggs Vegetarianism Nutrient concerns Strict vegans need B12 supplements Eat foods that possess complementary proteins Vegetarian diets may also lack vitamin D, riboflavin, calcium, iron, zinc But can be found in certain foods… Approaches to avoid nutrient deficiency in a vegetarian diet Vitamin D – moderate exposure to the sun or supplementation Riboflavin – consume green, leafy vegetables, whole grains and legumes Calcium – consume fortified soybean milk or orange juice, calcium-rich tofu and some cereals Iron – consume whole grains, dried fruits, nuts and legumes Zinc – consume whole grains, wheat germ, beans, nuts and seeds Soy products contain antioxidants Soy consumption is recommended as a replacement to meat consumption, but further research is needed to understand impact of soy on women Current recommendations in the University of California at Berkeley Wellness Letter: 1. Do not exceed 3 servings per day 2. Limit intake to a few servings per week if you have or have had breast cancer 3. Avoid soy supplements because they may contain more isoflavones than soy foods Probiotics Healthy microbes (bacteria) that help break down foods and prevent disease-causing organisms from settling in the intestines Example: Yogurts with Lactobacillus bifidus, Lactobacillus acidophilus and inulin Avoid yogurt with added fruit jam, sugar, and candy Advanced Glycation End Products (AGEs) Derivatives of glucose-protein and glucose-lipid interactions that are linked to aging and chronic diseases Decrease consumption of AGEs Limit cooking meats at high temperature Avoid high-fat foods Increase intake of fruits, vegetables, grains, fish and low-fat milk products Cook at home using fresh, unprocessed foods Avoid browning (frying, broiling and grilling) French fries have 8 time the amount of baked potatoes Diets from other cultures Mediterranean diet Focuses on olive oil, red wine, grains, legumes, vegetables and fruits, with limited amounts of meat, fish, milk and cheese Reduces rates of heart disease and cancer Other ethnic diets also provide health benefits by emphasizing intake of complex carbohydrates and limited fat-intake Diets from Other Cultures Nutrient supplementation A healthy diet of 1,500 calories contains the necessary nutrients Many people take supplements even though their diet contains sufficient nutrients Groups who may need nutrient supplementation Adults over 60 Individuals on low-calorie diets Individuals with nutrition deficiencies Avoid megadosing vitamins – consuming 10 times more than the RDA Anitoxidants Compounds such as vitamins C and E, betacarotene and selenium that prevent oxygen from combining with other substances in the body to form harmful compounds Work best as prevention and progression of disease, but cannot repair damage that has already occurred More research is required to understand the impact of antioxidants Antioxidants Free radicals attack and damage proteins, lipids, cell membranes, and DNA Free radical formation is enhanced by solar radiation, cigarette smoke, air pollution, radiation, some drugs, injury or infection, chemicals (such as pesticides), and other environmental factors Vitamin supplementation Vitamin E Found in oil-rich seeds and vegetable oils Little to no research demonstrates benefit Vitamin C May offer benefits against heart disease, cancer, and cataracts Body absorbs the first 200 milligrams per serving or dose and the rest is excreted Beta-Carotene Can be obtained from sweet potatoes, pumpkin, cantaloupe, squash, kale, broccoli, tomatoes, peaches, apricots Preferable to receive through food rather than supplementation Selenium Take 100-200 mcg daily One Brazil nut (unshelled) provides 100 mcg Top antioxidant foods Fruits and vegetables are the richest sources of antioxidants and phytonutrients Vitamin supplementation Multivitamins Vitamin D No solid scientific evidence that they decrease risk of cardiovascular disease or cancer May be able to fill deficiencies, but don’t provide energy, fiber, phytonutrients Best source is 15 minutes of sunshine daily Vitamin D levels in the blood should be between 50 and 80 ng/mL throughout the year Folate B vitamin that is recommended for all premenopausal women Benefits of Foods Choosing a wide variety of food is the best strategy to gain nutritional benefits. Supplements do not supply all of the nutrients and other beneficial substances present in food and needed for good health. Wholesome foods contain vitamins, minerals, carbohydrates, fiber, proteins, fats, phytochemicals, and other substances not yet discovered. Many nutrients work in synergy, enhancing chemical processes in the body. Functional Foods Foods or food ingredients containing physiologically active substances that provide specific health benefits beyond those supplied by basic nutrition Different than fortified foods which have been modified by the addition or increase of nutrients that either were not present or were present in insignificant amounts, with the intent of preventing nutrient deficiencies Organic Foods Is not more nutritious than non-organic food, but contains fewer pesticides Created under strict governmental regulations Cannot use genetically-modified organisms during the growth process Genetically modified crops Genetically modified food (GM) Basic genetic material is manipulated by inserting genes with desirable traits from one plant, animal or microorganism into another one to either introduce new traits or enhance existing ones No evidence indicates that GM foods are harmful, but no compelling evidence guarantees that they are safe Energy substrates for physical activity Two main fuels Glucose derived from foods is stored as glycogen in muscles and the liver. Fatty acids, the product of the breakdown of fats, stored as fat in the body Amino acids from proteins are used as an energy substrate when glucose is low. Energy substrates for physical activity The body uses Adenosine triphosphate (ATP) for immediate energy. It is resynthesized in 3 ways: 1. ATP-CP System Used in the first few seconds of all-out exercise 2. Anaerobic or lactic acid system Used during maximal intensity exercise from 10180 seconds Produces lactic acid which leads to muscle fatigue 3. Aerobic system Used during slow, sustained exercise and requires glucose, fatty acids and oxygen Nutrition for athletes Supplementation is not required for most athletes, but increased food intake may be needed Increased protein: Nutrition for athletes Carbohydrate loading replenishes glycogen storage, used for sustained exercise, greater than 90 minutes For exercise 60 minutes or less, 60 percent of carbohydrate intake should be maintained for the rest of the day For exhaustive exercise of several hours a day, 70 percent of carbohydrate intake should be maintained Within 30 minutes after exercise, a snack of protein and carbohydrate enhances re-storage of glycogen Nutrition for athletes Protect against hyponatremia by ingesting extra sodium prior to the event and replace with 1 gram of sodium per hour during an event Creatine supplementation Creatine is a higher-energy compound that the cells use to resynthesize ATP during all-out activities of very short duration Loading: 20-25 grams/day for 5-6 days split into four or five doses Maintenance: 2 grams/day Bone Health and Osteoporosis A condition that leads to softening, deterioration, or loss of bone mineral density Causes disability, fractures, and even death from medical complications About 22 million women in the U.S. suffer from this condition (16 million do not know they have it) Women are especially susceptible after menopause when estrogen is no longer produced One in 2 women and one in 8 men will suffer from osteoporosis Bone health and osteoporosis Promote bone health through adequate calcium intake and sufficient physical activity Calcium supplementation Calcium carbonate – not well absorbed without food Calcium citrate – absorbed without food Avoid eating an iron-rich meal with calcium supplement Excessive protein discourages rebuilding of bones Hormone replacement therapy (HRT) Originally provided to decrease bone loss after menopause HRT relieves acute symptoms of menopause and decreases risk of hip fractures and colorectal cancer HRT was found to increase risk for developing breast cancer, blood clots, strokes and heart disease Alternative therapies: Synthetic calcitonin Nonhormonal medications Selective estrogen receptor modulators Iron deficiency Iron is carried by hemoglobin: The protein-iron compound in red blood cells that transports oxygen in the blood Deficiency more common in women, endurance athletes, children and teenagers Iron levels are assessed through measurement of blood ferritin: The form of iron stored in the body RDA for adult women is 15-18 mg per day RDA for adult men is 8-11 mg per day Iron Deficiency 2010 Dietary Guidelines for Americans Two key concepts 1. Balance calories with physical activity to sustain a healthy weight 2. Focus on consuming nutrient-dense foods and beverages Fruits and vegetables Whole grains Fat-free and low-fat dairy products Seafood Visit: www.dietaryguidelines.gov 2010 Dietary Guidelines for Americans