Prentice6 ppt ch07
- 1. Chapter 7: Eating Right McGraw-Hill/Irwin © 2012 McGraw-Hill Companies. All Rights Reserved.
- 2. 7-2 Why do you need to know about nutrition? • Nutrition: – The science of certain food substances • Important terminology – nutrition - diuretics – diet - nutrient density – nutrients - requirement – deficiencies - recommendations – over-nutrition
- 3. 7-3 Basic Principles of Nutrition • Diet refers to food selection • Nutrients serve three major roles: – Growth, repair and maintenance of all body cells – Regulation of body processes – Supply of energy for cells • Some nutrients can be made by the body – Essential nutrients must be supplied by an individual’s diet
- 4. 7-4 • 6 major nutrients: – Carbohydrates – Fats – Protein – Water – Minerals – Vitamins • If all necessary nutrients are not brought into the body, nutritional deficiencies may develop Macronutrients Micronutrients
- 5. 7-5 • Overnutrition – Eating too much food or specific nutrients – Common problem in the United States – Can lead to obesity • Energy for the body – Energy value of food is measured in calories – Carbohydrates = 4 calories per gram – Fat = 9 calories per gram – Protein = 4 calories per gram – Alcohol = 7 calories per gram
- 7. 7-7 Carbohydrates (CHO) • Provides body with energy – While body will also run on fat and protein, CHO is preferred source of energy • 55% of total caloric intake should be accounted for by CHO • Classified into simple (sugars) or complex (starch, glycogen, fiber)
- 8. 7-8 • Sugars: – Simple carbohydrates that occur as single or double-sugar chemical units – Glucose (blood sugar) is needed to fuel cells – Must be careful not to consume too much sugar in diet (empty calories) • Starches: – Complex carbohydrates (long glucose chains) – Found in cereal grains, potatoes, and beans – Glycogen is broken down and released as glucose in the body when necessary
- 9. 7-9 • Fiber: – Helps individuals avoid constipation • Low fiber diets are blamed for intestinal problems – Also may be helpful in lowering blood cholesterol levels, which are a major risk factor for cardiovascular disease – Most forms are complex carbohydrates – Sources • Dietary and functional fiber • Fruits, vegetables, whole grain breads and cereals, nuts, beans, and peas
- 10. 7-10 Fats • Extremely important in one’s diet • Extra calories consumed as carbohydrates, proteins and fats can all be converted into triglycerides and stored for future use • Stored fat serves multiple functions: – Serves to cushion organs – Provides energy to muscles
- 11. 7-11 • Saturated vs. unsaturated fats: – Saturated fats are derived primarily from animal products • Found in meat (pork, chicken, beef), eggs, and dairy products • Also can be found in coconut and palm oils • Increase blood cholesterol levels – Unsaturated fats are liquid at room temperature • Contain omega-3 and omega-6 fatty acids • Found in vegetable and fish oils • Tend to be better for an individual
- 12. 7-12 • Cholesterol: – Fat-related substance found in animal foods – Believed to be responsible for creating blocked arteries – If enough is not consumed, your body will produce it naturally • Trans fatty acids: – Resemble saturated fatty acids – Results in hardening oils – Will boost levels of bad cholesterol – No safe level as there is no health benefit
- 13. 7-13 • Fat intake: – Total fat consumption vs. consuming specific fats – Makes up 40% of total calories consumed by Americans • Recommended levels (25-30%) – Cholesterol recommended levels = 300mg – Recommendations on reducing fat intake may be partially responsible for reducing cardiovascular deaths
- 14. 7-14 Protein • Required for growth, repair and maintenance of cells • Major constituent of all structures and organs of the body • Not a primary source of energy • Greater need for protein during periods of growth, breast feeding, active body- building
- 15. 7-15 • Recommendations: – 0.8 grams/kg of body weight – Should be approx. 12-15% of caloric intake • Proteins are composed of smaller sub-units (amino acids) – 20 amino acids in the body, 9 must be supplied by diet – All are necessary for growth – Primarily found in animal products, some in plants
- 17. 7-17 Water • Most essential nutrient: – 60% of the adult body is water • Required for energy production, maintaining cell function, and cooling of the body • Body requires 2.5 liters (10 glasses) daily • Sports drinks: – Allows for hydration, electrolyte and energy replacement – Better for re-hydrating, water itself can shut off thirst response and turn on kidney function prematurely
- 18. 7-18 Vitamins • Vitamins (13) serve as regulators in many body processes • Help to regulate metabolism and energy production, not a source of energy • Elderly, alcoholics, and those that restrict food intake severely are susceptible to vitamin deficiencies
- 19. 7-19 • Fat soluble vitamins: – Vitamins A, D, E, K – Found in fatty portion of foods and oils – Not easily eliminated from the body – Stored in liver and body fat – can make them potentially toxic • Water soluble vitamins: – Vitamin C, B-complex vitamins – Help to regulate metabolism but cannot be stored – Each serves a series of roles
- 20. 7-20 • Antioxidants: – May prevent premature aging, cancers, heart disease and other health problems – Helps protect cells from free radicals – Includes vitamins A, C, E – Found in a number of dark green, deep yellow and orange fruits and vegetables
- 21. 7-21 Minerals • More than 20 minerals have essential roles in the body, including: – Calcium – Iron • Many are stored in liver and bones • Required for a number of things: – Bones – Teeth – Activating enzymes – Energy production – Maintaining water balance
- 22. 7-22 Production of Energy • Occurs when cells break down chemical units of glucose and fats or amino acids – Must burn energy-supplying nutrients – Results in heat production and usable energy for cells to work – Proportions of nutrients burned depend on type, duration and intensity of exercise
- 23. 7-23 Nutrient Dense vs. Junk Foods • Nutrient dense – Foods containing considerable amounts of vitamins, minerals, and proteins in relation to their caloric content • Junk foods – Contain too many calories (through sugar and fats) in relation to the proportion of vitamins and minerals
- 24. 7-24 Nutrient Requirements and Recommendations • Requirement: – Amount of a nutrient that is needed to prevent nutrient deficiency disease • Recommendations: – Takes into account the amount necessary to avoid deficiency • US Recommended Dietary Allowances (USRDA): – Allows for comparison of the nutrition of food products • Dietary Reference Index (DRI) • Upper intake levels (UL) • Estimated average requirement (EAR) • Adequate intake (AI)
- 25. 7-25 Dietary Guidelines • Nutrition and health recommendations for healthy children and adults • In 2010, more emphasis was placed on helping consumers build healthier diets – Emphasizes fruits, vegetables, whole grains, fat-free or low-fat milk, lean meats/poultry, fish, beans, eggs and nuts • Actionable messages include: – Balance calories – Foods to increase – Foods to decrease
- 26. 7-26 MyPlate • 2011 campaign that focuses on healthier eating habits – Helps consumers build a healthy “plate” based around fruit, vegetables, grains, protein, and dairy – Identifies percentages of different types of food to eat in a given meal
- 27. 7-27 Reading Labels • Lists total calories and calories from fat per serving • Information that is based on percent daily values • Provides information on specific nutrients relative to % daily values
- 28. 7-28 What is the role of nutrition in physical activity? • Physically active people believe that certain nutrients can help in achieving fitness goals/competitive edge • Sometimes certain foods will be avoided by athletes
- 29. 7-29 Nutritional Supplements • Little evidence that vitamin, mineral or protein supplementation enhances physical performance: – Be a careful consumer – Generic vitamins and minerals are just as effective – Don’t be misled by labels – Consuming more than 150% of the recommended levels may be unhealthy – Supplements should not be a substitute for food
- 30. 7-30 Sugar • Ingesting large quantities of sugar prior to activity causes increased glucose in the blood • Release of insulin stimulated, allowing cells to utilize free-circulating glucose, sparing blood glucose • Positive effect on performance • However, some athletes are sensitive to high CHO feedings and have problems with increased levels of insulin
- 31. 7-31 Caffeine • Central nervous system stimulant found in carbonated beverages, coffee, tea • Increases alertness and decreases fatigue • Too much causes nervousness, irritability, increased heart rate and headaches
- 32. 7-32 Alcohol • Provides energy for the body • Little nutritional value • Central nervous system depressant • Not wise to replace water with alcohol before, during, or following activity • Too much alcohol can damage liver and brain cells
- 33. 7-33 Herbs • Safe to ingest as natural medicines with few side effects (occasional allergic reaction) • No federal or governmental regulations on quality or distribution – Exercise caution with consumption • Herbs serve as body balancers that work with functions of the body • Uses may be general for overall strength and nutrient support or specific to a condition or ailment
- 34. 7-34 The Problem with Eating Fast Food • 40-50% of calories consumed in fast food are fat calories • Add the “supersize” label and the problem is compounded • Some fast food establishments have worked to broaden their menu to include healthier options • Nutritional information is also available for the consumer
- 35. 7-35 Pre-event Meal • Long term food consumption is more important than immediate consumption • Purpose should be to provide competitor with nutrients/energy and fluids for competitions – A light (300 calories) meal 2-4 hours before is encouraged • Avoid a full stomach and fatty foods • Preloading with water is also suggested
- 36. 7-36 Vegetarianism • Utilizes plants to form foundation of diet • Economic, philosophical, religious, cultural, or health reasons • Diet must be carefully planned • Total vegetarian (vegan): No animal products • Lactovegetarian: Consumes plant and milk products • Ovolactovegetarian: Consumes plant, milk, and egg products • Semivegetarian: Does not consume red meats
- 37. 7-37 Food Safety • Must be careful both with food preparation and consumption • Foodborne illness: – Result of bacteria in food – Raw foods are most common source due to lack of sterilization • Can happen in your kitchen if food left out for 2 or more hours at room temperature • Treatment: – Increase fluid intake; hospitalization if more serious