Presentation on theme: "Author name here for Edited books chapter 9 9 Designing Weight Management and Body Composition Programs chapter."— Presentation transcript:
Author name here for Edited books chapter 9 9 Designing Weight Management and Body Composition Programs chapter
Objectives Understand the prevalence of obesity Differentiate between health risks for carrying too much and too little body fat Identify healthy body weight targets Design a scientifically sound weight management program Understand the role of exercise in a sound weight management program
Definitions and Classifications Obesity: excessive amount of body fat relative to body weight; body mass index (BMI) at least 30.0 kg/m 2 Overweight: BMI between 25 and 29.9 kg/m 2 Underweight: BMI less than 18.5 kg/m 2 To identify children and adolescents who are overweight, the 85th and 95th percentile BMI values are used; cutoffs for age and sex are still under discussion.
Trends in Overweight and Obesity According to World Health Organization (2007): –More than 1.6 billion adults are overweight. –Over 400 million are obese. –By the year 2015 the number of overweight people globally is estimated to increase to 2.3 billion. (continued)
Trends in Overweight and Obesity (continued) Adults: Prevalence of overweight and obesity varies among countries, depending in part on the level of industrialization. –In the U.S., 34% are obese (BMI > 30 kg/m 2 ), –2 out of 3 are overweight (BMI = 25-29.9 kg/m 2 ) (continued)
Trends in Overweight and Obesity (continued) Children and adolescents (6-19 years): Prevalence at risk for overweight (BMI of 85th-95th percentile) in Canada and the United States ranges from 29% to 35%.
Types of Obesity Android: typically male pattern; apple shape; localization of excess body fat mainly in the upper body; upper-body obesity Gynoid: typically female pattern; pear shape; localization of excess body fat mainly in the lower body; lower-body obesity
Causes of Overweight and Obesity Physical inactivity Overeating Positive energy balance: energy consumed (food and beverages) exceeds energy expended (exercise plus resting energy expenditure) –3,500 kcal equals 1 pound –Will be stored or lost depending on direction of energy balance (positive or negative)
Basal Metabolic Rate (BMR) Measure of the minimal energy (kcal) needed to maintain basic and essential physiological functions Varies according to age, gender, body size, and body composition Assessed in a controlled environment with the individual in a rested and fasted state
Resting Metabolic Rate Practical alternative to BMR Defined as energy required to maintain essential physiological processes in a relaxed, awake, and reclined state Also known as resting energy expenditure (REE)
Total Energy Expenditure (TEE) TEE = (BMR or RMR) + dietary thermogenesis + physical activity TEE estimated via age- and gender-specific prediction equations Dietary thermogenesis: energy needed for digesting, absorbing, transporting, and metabolizing foods
Weight Management Principles and Practices Key components: proper nutrition and physical activity Weight management does not always mean weight loss; client may need to gain weight. The best method for negative energy balance is a combination of dietary restriction and exercise. To gain weight, client must maintain positive energy balance.
Physically Active Lifestyle Daily aerobic exercise Strength and flexibility exercises Increased recreational and leisure time physical activities Increased physical activity in the daily routine at home and work—restricted use of labor-saving devices
Healthful Eating Consume a variety of nutrient-dense foods within and among the basic food groups. Limit intake of saturated and trans fats, cholesterol, added sugars, salt, and alcohol. Meet recommended intakes within energy needs by adopting a balanced eating pattern.
Weight Management To maintain healthy body weight, balance calories from foods and beverages with calories expended. To prevent gradual weight gain, make small decreases in food and beverage calories and increase physical activity.
Physical Activity Engage in at least 30 minutes of moderate-intensity physical activity, above ADLs and occupational requirements, on most days of the week. Greater health benefits are obtainable by engaging in more vigorous or longer bouts of physical activity. (continued)
Physical Activity (continued) To manage and maintain healthy body weight, engage in ~60 minutes of moderate- to vigorous- intensity exercise, most days of the week, and eat within caloric intake requirements. To sustain weight loss, participate in at least 60 to 90 minutes of daily moderate-intensity physical activity and eat within caloric intake requirements (continued)
Physical Activity (continued) Achieve physical fitness by including –cardiovascular conditioning, –stretching exercises for flexibility, and –resistance exercises or calisthenics for muscle strength and endurance.
Food Groups to Encourage Sufficient amount of fruits and vegetables while staying within energy needs Selections from all five vegetable subgroups several times a week Daily: –Variety of fruits and vegetables –At least 3 ounces of equivalents of whole-grain products with the rest of the recommended grains from enriched or whole- grain products –3 cups per day of fat-free or low-fat milk or equivalent milk products
Carbohydrates (CHOs) Select fiber-rich fruits, vegetables, and whole grains. Select foods and beverages with little added sugar or caloric sweeteners. Limit consumption of sugar- and starch-containing foods and beverages.
Sodium and Potassium Consume less than 2,300 mg (~ 1 tsp of salt) of sodium per day. Choose and prepare foods with little salt. Consume potassium-rich foods such as fruits and vegetables.
Alcoholic Beverages Those who drink should practice responsible drinking: one or fewer drinks per day for women and two or fewer drinks per day for men. Alcohol consumption should be completely avoided in many situations.
Well-Balanced Nutrition IOM (2002) recommends following percentage contribution, by food group, for a well-balanced nutritional plan for adults: –45% to 65% of their calories from CHOs –20% to 35% of their calories from fat –10% to 25% of their calories from protein
Carbohydrates Major types: –Simple CHOs: simple sugars found in fruits, berries, some vegetables, table sugar, and honey –Complex CHOs: found in many plant-based foods, whole grains, and low-fat dairy products Experts tout health benefits of consuming wide range of CHOs with emphasis on fruits, vegetables, whole grains, and low-fat dairy products. (continued)
Carbohydrates (continued) To maintain and replenish glycogen stores, you need a daily CHO intake of –7 to 8 g·kg –1 of body weight if you engage in low- intensity, moderate-duration physical activity. –7 to 12 g·kg –1 of body weight if you engage in high- intensity or long-duration exercise.
Protein Essential amino acids are needed for protein synthesis. In general, daily protein requirement of the body is ~0.8 g·kg –1 of body weight. For endurance athletes recommended intake is 1.2 to 1.4 g·kg –1 of body weight. Strength-trained athletes may need as much as 1.7 g·kg –1 of body weight.
Fats Some dietary fat is needed to supply fatty acids and to absorb fat-soluble vitamins. Fats must be chosen wisely. To promote weight loss and to reduce serum cholesterol level, limit these intakes: – saturated fat and trans fatty acids (<7% of total calories) –total fat (25% to 35% of total calories) –cholesterol (<200 mg per day)
Vitamins No need to supplement if diet is balanced. Those restricting food intake to lose weight or make weight, may benefit from supplementation. Supplementation is beneficial only for those who are deficient in one or more vitamins.
Minerals Physically active individuals, particularly vegetarians, may need to supplement iron and zinc. Iron requirements for endurance athletes (e.g., distance runners) are increased by 70% (ACSM 2009). For athletes with eating disorders, amenorrhea, and risk for early osteoporosis, 1,500 mg of elemental calcium and 400-800 IU of vitamin D per day are recommended (ACSM 2009).
Vitamin and Mineral Supplementation Facts Vitamin B 12 supplementation does not increase muscle growth or strength. Carnitine (a vitamin-like compound) supplementation does not facilitate loss of body fat. Chromium supplementation does not increase fat-free mass or decrease body fat. Boron supplementation does not increase serum testosterone or fat-free mass. Magnesium supplementation does not improve muscle strength.
Water Athletes and physically active individuals need to –hydrate before exercise, –drink fluids during exercise, and –rehydrate immediately after exercise.
Prehydration, Hydration, and Rehydration Guidelines for hydration: –About 4 hours before exercise, drink 5 to 7 ml/kg of body weight of water or a sport beverage. –Replace fluids depending on sweat rate, exercise duration, and opportunities to drink. –Drink at least 6 ounces of fluid every 15 to 20 minutes. –Consume drinks containing CHO (6-8%) and sodium when endurance exercise is more than 1 hour. –Drink at least 16 ounces of fluid for every pound of body weight lost during exercise.
Designing Weight-Management Programs: Preliminary Steps 1.Set body weight goals. 2.Assess calorie intake and energy expenditure. 3.Design weight-loss program inclusive of caloric restriction plus exercise program. 4.Work closely with a licensed nutritionist or registered dietitian when planning diets for your clients.
Weight-Loss Diets Are all calories created equal? Low-carbohydrate (carb) isocaloric diets (e.g., Atkins) result in rapid short-term weight loss in obese adults; shown to improve triglyceride and HDL-C levels. High-protein or low-carb diets result in great 3- to 6- month weight losses; high-protein diets increase satiety and may thereby reduce daily caloric intake. Long-term effect of macronutrient restrictive diets is not yet known. (continued)
Weight-Loss Diets (continued) Research shows that weight loss depends on calorie intake and not on the macronutrient composition of the diet. An effective strategy for reducing energy (calorie) intake is to eat less refined, processed food as well as less saturated and trans fat. A balanced diet contains adequate amounts of good sources of carbohydrate, protein, and fat (table 9.8). Healthy Eating Pyramid: –Foundation of daily physical activity and weight control –Recommendations for food choices that promote health and weight control
Exercise for Weight Loss For health benefits according to ACSM (2008): –At least 30 minutes of moderate-intensity (3-6 METs) activity at least 5 days a week or –20 minutes of vigorous-intensity (>6.0 METs) for a minimum of 3 days a week (continued)
Exercise for Weight Loss (continued) Alternatively, according to the 2008 Physical Activity Guidelines for Americans, health benefits are achieved with –150 to 300 minutes a week of moderate-intensity (3- 6 METs) exercise or –75 to 150 minutes a week of vigorous-intensity (≥ 6.0 METs) exercise. (continued)
Exercise for Weight Loss (continued) Preventing weight gain: –Moderate-intensity physical activity between 150 and 250 minutes a week (ACSM 2009) –45 to 60 minutes of moderate- to vigorous-intensity activity on most, preferably all, days (IOM, 2002) –For children and adolescents, at least 60 minutes of moderate- to vigorous-intensity physical activity daily (continued)
Exercise for Weight Loss (continued) Preventing weight regain: –Specific amount of physical activity needed to prevent weight regain is uncertain. –About 60 minutes a day of walking at a moderate intensity is associated with weight maintenance (ACSM 2009). –At least 60 minutes, but preferably 80 to 90 minutes, of moderate-intensity physical activity and exercise recommended per day (IOM 2002).
Benefits of Exercise in Weight Management Increases energy expenditure Helps create a negative energy balance for weight loss Promotes fat loss and preservation of LBM Maintains or slows down FFM loss resulting from weight loss via diets only Helps maintain weight loss after dieting Increases RMR
Types of Exercise in Weight Management Aerobic exercise is effective for weight loss, fat loss, and long-term weight management. Resistance training increases muscle mass and REE; it does not produce much weight loss. Resistance training may increase fat loss when combined with aerobic exercise.
Exercise Intensity and Weight Management Weight loss and fat loss are positively related to weekly energy expenditure. At a constant energy expenditure, total fat oxidation is higher during low-intensity compared to high-intensity exercise. Exercise duration may be key for fat loss. Most obese clients prefer a slower pace and low- to moderate-intensity exercise.
Designing Weight-Gain Programs First, rule out the possibility that diseases and psychological disorders associated with malnutrition are causing low weight level. A caloric excess of 2,800 to 3,500 kcal is required to gain 1 pound. Adding 400 to 500 kcal to the estimated daily caloric needs can result in a gain of 1 pound a week. Adjust caloric intake to cover exercise energy expenditure.
Exercise Prescription for Weight Gain Prescribe resistance training to increase muscle size. A high-volume resistance training program maximizes muscle size best. Novice weightlifters should start slowly. See text for recommended guidelines for developing an exercise prescription for weight gain.
Designing Programs to Improve Body Composition You can decrease subcutaneous fat, fat weight, and percent body fat of adults with aerobic and resistance exercise. No type of aerobic exercise training is better than another for fat loss. Frequency of 4 days a week is found to be superior to 3 days a week. Combining aerobic and resistance training exercises produces effective change in body composition of nondieting individuals.