chapter
chapter
99
Designing Weight
Management and
Body Composition
Programs
Author name here for Edited books
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/m2
• Overweight: BMI between 25 and 29.9 kg/m2
• Underweight: BMI less than 18.5 kg/m2
• 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/m2),
– 2 out of 3 are overweight (BMI = 25-29.9 kg/m2)
(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 vigorousintensity 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 wholegrain 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.
Weight Management Principles
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 lowintensity, moderate-duration physical activity.
– 7 to 12 g·kg–1 of body weight if you engage in highintensity 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 B12 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.
Steps for Designing a Weight Loss
Program
Steps for Designing a Weight Loss
Program
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 6month 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 (36 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).
Table 9.9
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.