Skip to main content
UploadLanguage (EN)Support
BusinessMobileSocial MediaMarketingTechnologyArt & PhotosCareerDesignEducationPresentations & Public SpeakingGovernment & NonprofitHealthcareInternetLawLeadership & ManagementAutomotiveEngineeringSoftwareRecruiting & HRRetailSalesServicesScienceSmall Business & EntrepreneurshipFoodEnvironmentEconomy & FinanceData & AnalyticsInvestor RelationsSportsSpiritualNews & PoliticsTravelSelf ImprovementReal EstateEntertainment & HumorHealth & MedicineDevices & HardwareLifestyle
Uploaded bytbrame
PPT, PDF15,695 views

Nutrition and Your Diet

This chapter discusses the key nutrients required for a healthy diet including carbohydrates, fats, proteins, vitamins, minerals, water and fiber. It provides details on the functions and sources of these nutrients and recommends intake amounts. The chapter also covers dietary guidelines, tools for planning a nutritious diet like MyPyramid and issues related to food labels, fast food, functional foods, supplements, allergies and safety.

Health & Medicine◦Business◦
Downloaded 2,060 times
Chapter 5 Understanding Nutrition and Your Diet
Nutrients Nutrients = elements in food that are required for the growth, repair, and regulation of body processes Carbohydrates Fats Protein Vitamins Minerals Water Fiber
Carbohydrates Major energy source: 4 calories/gram Types Monosaccharides Disaccharides Polysaccharides Recommended intake: 45-65% of total calories from carbohydrates
Carbohydrates Simple sugars Average American adult consumes about 140 pounds of sweeteners each year Sugar, corn sweetener, syrup, honey Sodas, candy, bakery and processed goods
Fats Functions: Insulation, carrier of vitamins, storage of long-term energy, and satiety Energy source: 9 calories/gram Types Saturated Monounsaturated Polyunsaturated Trans Recommended intake: 20-35% of total calories
Types of Fats Saturated fats Solid at room temperature Primarily found in animal fats Negative effects on heart health Monounsaturated and polyunsaturated fats Liquid at room temperature Vegetable oils Positive effects on heart health Omega-3 polyunsaturated fats found in fish are considered especially healthful
Composition of Dietary Fats
Types of Fats: Trans Fats 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 Check food labels
Types of Fats: 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
Fats: General Recommendations 20-35% of total daily calories from fat Less than 10% of calories from saturated fat Less than 300 mg/day of cholesterol Keep trans-fatty acid consumption as low as possible Get most fats from sources of unsaturated fats Fish Nuts Vegetable oils
Fats Low-fat does not necessarily mean low-calorie Higher price tag Low-fat dairy and salad dressings have less saturated fat Low-fat foods
Protein Functions: Growth and maintenance of tissue, acid-base balance Energy source: 4 calories/gram 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
Protein Complete protein sources supply all essential amino acids Animal foods, soybeans Incomplete protein sources supply some but not all essential amino acids Plant foods Recommended intake: 10-35% of total calories
Vitamins Organic compounds needed in small amounts for normal growth, reproduction, and maintenance of health Serve as co-enzymes Provide no energy: 0 calories/gram Types Water soluble B-complex vitamins and vitamin C Fat soluble Vitamins A, D, E, K
Vitamins: Should I Take a Supplement? Following dietary recommendations would allow most Americans to meet their nutrient needs without supplements Many people eat too many nutrient-deficient foods Caution with using supplements Hypervitaminosis = toxicity Megadoses of any vitamin can be harmful Recommendations for certain groups Folic acid, vitamin B-12, vitamin D
Phytochemicals Phytochemicals = physiologically active components of foods that may deactivate carcinogens Many phytochemicals function as antioxidants May protect cells from damage caused by unstable molecules (“free radicals”) Examples Carotenoids Polyphenols Allyl sulfides
Minerals Inorganic materials that act as structural elements and regulators of numerous body processes Provide no energy: 0 calories/gram Types Macronutrients: “Major minerals” found in high amounts in the body Micronutrients: “Trace elements” found in small amounts in the body
Water and Fluids Average adult loses about 10 cups of water per day Urination, bowel movements, breathing, perspiration Functions: Provide medium for nutrients, waste transport, temperature control For every pound of body weight, you need about 0.5 ounce of fluid Sources: Beverages, fruits, vegetables
Fiber Cellulose-based plant material that cannot be digested Provides no energy: 0 calories/gram Types: Soluble (gel-forming) Insoluble (absorbs water) Benefits Moves stool through digestive tract Lowers blood cholesterol levels Steadies blood sugar levels Recommended: 21-38 grams/day Most American adults: 11 grams/day
Dietary Reference Intakes Dietary Reference Intakes (DRIs) = recommended nutrient intakes Estimated Average Requirement (EAR) Recommended Dietary Allowance (RDA) Tolerable Upper Intake Level (UL) Acceptable Macronutrient Distribution Range (AMDR)—percent of total daily calories 45-65% as carbohydrate 20-35% as fat 10-35% as protein
Tools for Planning a Healthy Diet The USDA Food Guide: MyPyramid The Dietary Guidelines for Americans
MyPyramid
 
MyPyramid Personalized approach Amounts recommended from each food group vary based on age, gender, and activity level Visit www.mypyramid.gov Balance food intake and physical activity
MyPyramid Food Groups Fruits 2 cups/day for a 2,000-calorie diet Eat a variety of fruits Favor whole fruits over fruit juices Vegetables 2½ cups/day for a 2,000-calorie diet Eat a variety of vegetables Dark green vegetables Orange vegetables Legumes Starchy vegetables Other vegetables
MyPyramid Food Groups Milk and milk products 3 cups/day for a 2,000-calorie diet Favor fat-free or low-fat products Vegans and those who are lactose intolerant should choose other sources of calcium
MyPyramid Food Groups Meat, poultry, fish, eggs, dry beans, and nuts 5 1 / 2 ounce-equivalents for a 2,000-calorie diet 1 ounce equivalents: 1 ounce cooked meat, poultry, fish 1 egg 1 / 4 cup legumes or tofu 1 tablespoon peanut butter 1 / 2 ounce nuts or seeds Choose lean and low-fat foods
MyPyramid Food Groups Breads, cereals, rice, and pasta 6 ounces/day for a 2,000-calorie diet 3 or more ounces/day should be whole grains 1 ounce equivalents: 1 slice bread 1 cup dry cereal 1 / 2 cup cooked rice, pasta, cereal
MyPyramid Food Groups Oils (vegetable oils, fish, nuts, seeds) 24 grams or 6 teaspoons/day for a 2,000-calorie diet 1 teaspoon equivalents: 1 teaspoon vegetable oil or margarine 1 tablespoon low-fat mayonnaise 2 tablespoons light salad dressing Discretionary calories
Dietary Guidelines for Americans Adequate nutrients within calorie needs Consume nutrient-dense foods within and among the food groups Weight management Balance calories from foods and beverages with calories expended Make small decreases in calorie intake to prevent gradual weight gain over time
Dietary Guidelines for Americans Physical activity Regular moderate physical activity 30 minutes/day to reduce risk of chronic disease 60 minutes/day to prevent gradual, unhealthy weight gain 60-90 minutes/day to sustain weight loss Decrease sedentary activities
Dietary Guidelines for Americans Food groups to encourage Fruits Vegetables Milk Fats Total fat: 20-35% of total calories Saturated fat: <10% of total calories Cholesterol: <300 mg/day Limit trans fats
Dietary Guidelines for Americans Carbohydrates Choose whole grains often Limit added sugars Sodium and potassium Sodium: Consume less than 2,300 mg/day (about 1 teaspoon of salt) Potassium: Consume potassium-rich foods such as fruits and vegetables
Dietary Guidelines for Americans Alcoholic beverages Those who choose to drink should do so sensibly and in moderation Up to 1 drink/day for women Up to 2 drinks/day for men Food safety Take steps to avoid microbial foodborne illness
Vegetarian Diets Reliance on plant sources for most of the nutrients the body needs Ovovegetarian: Includes eggs Lactovegetarian: Includes dairy Ovolactovegetarian: Includes eggs and dairy Vegan: Excludes all animal products Requires more planning Need to maintain adequate intake of vitamin B-12, calcium, iron, zinc, vitamin D Semivegetarian: Great reduction (but not elimination) of meat products Pescovegetarian: Includes fish, eggs, dairy products
MyPyramid for Ovolacto-vegetarians
Food Labels Required by the FDA since 1973 New in 2006 Amount of trans fat Proteins derived from major food allergen sources
Nutrition Facts Label
Fast Foods Fat density of fast foods 40-70% of calories in fast foods is fat Recommended intake: 20-35% of total daily calories from fat Most people underestimate the calorie content in a fast food meal by as much as 500 calories
Functional Foods Foods capable of contributing to the improvement or prevention of specific health problems Probiotics: Living bacteria that help prevent disease and strengthen the immune system (e.g., yogurt) Garlic, olive oil, high-fiber foods, calcium-rich foods, antioxident-rich foods Foods enriched with folic acid
Dietary Supplements Products that supplement the total daily intake of nutrients in the diet Ingested in tablet, capsule, softgel, gelcap, and liquid form Not in themselves used as conventional foods or as the only items in a meal or diet Must be deemed safe for human Cannot claim to cure or treat diseases Americans spent over $19 billion on supplements (in 2005)
Food Allergies Allergy = reaction in which the immune system attacks an otherwise harmless food or ingredient Different from a food intolerance, which is usually caused by an enzyme deficiency Common food allergens include peanuts, milk, soy products, shellfish, and wheat Allergic reactions can develop slowly over several exposures Symptoms range from mildly unpleasant to life threatening
Food Safety Preventing foodborne illness Safe handling, cooking, and storage of foods
Food Safety Food irradiation Use of radiation to kill foodborne pathogens Safe farming techniques More humane treatment of farm animals Improved food quality Reduced exposure to antibiotic-resistant bacteria, prions (cause of “mad cow disease”), and chemicals
Food Safety Organic foods No use of growth hormone or antibiotics Not genetically engineered or irradiated No use of chemical fertilizers or sewage sludge Diseases, pets, and weeds treated or controlled primarily with nonchemical means
Food Safety Food additives Provide color or flavor Replace sugar or fat Improve nutritional content, texture, or shelf life FDA tested Genetically modified foods Altered to improve yields and reduce costs
Chapter Five: Understanding Nutrition and Your Diet