body composition body composition involves all components of

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Body Composition Body composition involves all components of the body including: Fat mass Muscle mass Bone mass Water volume

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Page 1: Body Composition Body composition involves all components of

Body Composition

Body composition involves all components of the body including:

Fat massMuscle massBone massWater volume

Page 2: Body Composition Body composition involves all components of

Body Composition

We’ve talked about muscle mass, so this section will focus on fat management.

Page 3: Body Composition Body composition involves all components of

Body Composition

ObesityMay be functionally defined as the

percent body fat at which disease risk increases.

Page 4: Body Composition Body composition involves all components of

Body Composition

Obesity is an excessive amount of body fat relative to body weight and is not synonymous with overweight.

Page 5: Body Composition Body composition involves all components of

Body Composition

In epidemiological studies:overweight is >120% of desirable

weightbody mass index (BMI) >29.3 for

women and 29.8 for men.

Page 6: Body Composition Body composition involves all components of

Body Composition

Because these overweight criteria do not take into account the composition of the excess weight, they are limited as indexes of obesity and may result in misclassifications of obesity.

Page 7: Body Composition Body composition involves all components of

Body Composition

An excessive percentage of body fat is associated with increased risk for development of hypertension, diabetes, CAD, and other chronic diseases.

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Body Composition

The prevalence of hypercholesterolemia, hypertension, and Type II diabetes is, respectively 2.9, 2.1, and 2.9 times greater in overweight than in non-overweight persons.

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Body Composition

Recent evidence indicates that “central obesity” is particularly problematic.

Abdominal fat is strongly associated with diseases such as CHD, diabetes, hypertension, and hyperlipidemia.

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Body Composition

Android and Gynoid Obesity

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Body Composition

In addition, obesity often carries negative social stigma and is associated with a reduced physical working capacity.

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Body Composition

At the opposite extreme, individuals with too little body fat tend to be malnourished.

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Body Composition

These people have a relatively higher risk of fluid-electrolyte imbalances, osteoporosis and osteopenia, bone fractures, muscle wasting, cardiac arrhythmias, and sudden death, edema, and renal and reproductive disorders.

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Body Composition

One disease associated with extremely low body fat levels is anorexia nervosa.

Page 15: Body Composition Body composition involves all components of

Body Composition

Anorexia nervosa is an eating disorder found primarily in females and is characterized by excessive weight loss.

Page 16: Body Composition Body composition involves all components of

Body Composition

Compared to normal women, anorexics have extremely low body fat levels (8 to 13%), signs of muscle wasting, and less bone mineral content and bone density.

Page 17: Body Composition Body composition involves all components of

Body Composition

Combating obesity and eating disorders is not an easy task.

Page 18: Body Composition Body composition involves all components of

Body Composition

Many overweight and obese individuals have incorporated patterns of overeating and physical inactivity into to their lifestyles, while others have developed food and/or exercise addictions.

Page 19: Body Composition Body composition involves all components of

Body Composition

Many are lured by fad diets and exercise gimmicks, and some resort to extreme behaviors such as avoiding food, bingeing and purging, and exercising compulsively.

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Body Composition

Body fat is reduced when a chronic negative caloric balance exists.

Page 21: Body Composition Body composition involves all components of

Body Composition

It is recommended that both an increase in caloric expenditure through exercise and a decrease in caloric intake be used to accomplish this goal.

Page 22: Body Composition Body composition involves all components of

Body Composition

Exercise increases energy expenditure and slows the rate of fat-free tissue loss that occurs when a person loses weight by severe caloric restriction.

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Body Composition

Exercise also helps maintain the resting metabolic rate and thus the rate of weight loss.

Page 24: Body Composition Body composition involves all components of

Body Composition

Hormones play an important role in regulating metabolism.

Page 25: Body Composition Body composition involves all components of

Body Composition

Thyroxine is extremely important in regulating resting metabolic rate.

Underproduction of thyroxine can reduce RMR 30 to 50%.

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Body Composition

Growth hormone, epinephrine, norepinephrine, and various sex hormones may elevate RMR as much as 15 to 20%.

Page 27: Body Composition Body composition involves all components of

Body Composition

These hormones increase during exercise and may be responsible for the elevation in resting metabolic rate after cessation of exercise.

Page 28: Body Composition Body composition involves all components of

Body Composition

Improper diet, overeating, hormonal disturbances, and physical inactivity may create a positive energy balance, which leads to excessive weight gain and obesity.

Page 29: Body Composition Body composition involves all components of

Body Composition

Lack of physical activity rather than overeating is a more common cause of obesity in children and adults.

Page 30: Body Composition Body composition involves all components of

Body Composition

Obese individuals are invariably sedentary and many have had poor experiences with exercise in the past.

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Genetics

Only 10% of children who had normal-weight parents were obese.

Page 32: Body Composition Body composition involves all components of

Genetics

The probability of being obese is increased to 40% and 80%, respectively, if one parent or both parents are obese.

Page 33: Body Composition Body composition involves all components of

Genetics

Although these data suggest a strong genetic influence, they do not rule out environmental influences such as eating and exercise habits.

Page 34: Body Composition Body composition involves all components of

Genetics

Approximately 25% of the variability among individuals in absolute and relative body fat is attributed to genetic factors and 30% is associated with cultural (environmental) factors.

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Body Composition

The exercise professional should interview the obese participant to determine past exercise history, potential scheduling difficulties, and the locations where exercise might be performed (e.g., sports club, home, street, school gym, or track, etc.)

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Body Composition

This may increase adherence to an agreed upon exercise program.

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Psychological Issues

Overweight and obesity may be caused by psychological factors.

Page 38: Body Composition Body composition involves all components of

Psychological Issues

Some overweight and obese individuals use food and eating as a coping mechanism or defense mechanism.

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Psychological Issues

Compulsive eaters may eat to cope with feelings of insecurity, anxiety, depression, loneliness, stress, and tension rather than to satisfy hunger.

Page 40: Body Composition Body composition involves all components of

Psychological Issues

In this case, the individual needs to recognize the fact that he or she is eating compulsively, identify the underlying reasons for this behavior, and take steps to modify these behaviors.

Page 41: Body Composition Body composition involves all components of

Psychological Issues

Encourage clients with eating disorders to seek psychological counseling.

Page 42: Body Composition Body composition involves all components of

Body Composition

Obesity is associated with increases in both the number (hyperplasia) and size (hypertrophy) of fat cells.

Page 43: Body Composition Body composition involves all components of

Body Composition

An increase in fat cell number occurs rapidly during the last trimester in the womb through the first year of life, around ages 7-8, and again during adolescence, but remains fairly stable in adulthood except in cases of morbid obesity.

Page 44: Body Composition Body composition involves all components of

Body Composition

Fat cells grow in size when excess fat is stored in the cells as triglycerides.

Weight gain in adults is typically characterized by the enlargement of existing fat cells, rather than the creation of new fat cells.

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Body Composition

Similarly, caloric restriction and exercise are effective in reducing fat cell size, but not the number of fat cells.

Page 46: Body Composition Body composition involves all components of

Body Composition

The key to preventing obesity is to closely monitor the dietary intake and energy expenditure, especially during the adolescent growth spurt and puberty.

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Body Composition

This could potentially retard the development of new fat cells and control the size of existing fat cells.

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Lifestyle Change

Adoption of a physically active lifestyle.

Adoption of dietary guidelines. (US Dept. of Health and Human

Services, 1995)

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Dietary Guidelines

Eat a variety of foods.Balance the food you eat with

physical activity.Choose a diet with plenty of grain

products, vegetables, and fruits.

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Dietary Guidelines

Choose a diet low in fat, saturated fat, and cholesterol.

Choose a diet moderate in sugars.Choose a diet moderate in salt and

sodium.

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Dietary Guidelines

If you drink alcoholic beverages, do so in moderation.

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Behavior Modification

Behavior modification techniques can help people make these lifestyle changes.

Page 53: Body Composition Body composition involves all components of

Behavior Modification

Exercise specialists, nutritionists, and psychologists need to work together to help their clients, especially obesity prone individuals, modify their physical activity and eating attitudes and behaviors.

Page 54: Body Composition Body composition involves all components of

Body Comp. - Fat Loss

The initial exercise prescription should be based on low intensity and progressively longer durations of activity.

Page 55: Body Composition Body composition involves all components of

Body Composition

On the basis of each person’s response to the initial exercise program, the exercise professional should eventually work toward increasing the intensity to bring the person into a target heart rate range suitable for cardiorespiratory conditioning.

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Body Composition

The higher intensity will allow for a shorter duration per session, or fewer sessions per week for the same weekly energy expenditure.

Page 57: Body Composition Body composition involves all components of

Body Composition

In addition, the transition to higher intensity exercise will increase the number of opportunities to incorporate activities that naturally require a high rate of energy expenditure.

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Body Composition

However, for many (especially older) obese subjects, a walking or other low intensity exercise program may be all they desire, and movement toward a more intense program may not be warranted.

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Body Composition

The needs and goals of the obese subject must be individually matched with the proper exercise program to achieve long-term body composition management.

Page 60: Body Composition Body composition involves all components of

Caloric Balance

Body composition is determined by a complex set of genetic and behavioral factors.

Page 61: Body Composition Body composition involves all components of

Caloric Balance

Though the contributing variables are many, the fundamental determinant of body weight and body composition is caloric balance.

Page 62: Body Composition Body composition involves all components of

Caloric Balance

Caloric balance refers to the difference between caloric intake and caloric expenditure.

Page 63: Body Composition Body composition involves all components of

Caloric Balance

The First Law of Thermodynamics states that energy is neither created nor destroyed; therefore, body weight is lost when caloric expenditure exceeds caloric intake (negative balance) and weight is gained when the opposite situation exists.

Page 64: Body Composition Body composition involves all components of

Caloric Balance

One pound of body fat (adipose tissue) is equivalent to approximately 3500 kcal of energy.

Page 65: Body Composition Body composition involves all components of

Caloric Balance

Although it is predictable that shifts in caloric balance will be accompanied by changes in body weight, the nature of the weight change varies markedly with the specific behaviors that lead to the caloric imbalance.

Page 66: Body Composition Body composition involves all components of

Caloric Balance

For example, fasting and extreme caloric restriction (starvation and semi-starvation diets) cause substantial losses of water and fat-free tissue.

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Caloric Balance

In contrast, an exercise-induced negative caloric balance results in weight loss consisting primarily of fat.

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Caloric Balance

High resistance exercise programs may lead to a gain in fat-free weight, while cardiorespiratory endurance training usually results in a maintenance of (or slight increase in) fat-free weight.

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Caloric Balance

Both types of programs can contribute to a loss of body fat, although aerobic activity is more efficient because it involves a sustained, high rate of energy expenditure.

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Recommendations

For most persons, the optimal approach to fat loss combines a mild caloric restriction with regular endurance exercise and avoids nutritional deficiencies.

Page 71: Body Composition Body composition involves all components of

Recommendations

A desirable fat loss program is one that meets the following criteria:

Page 72: Body Composition Body composition involves all components of

Recommendations

1. Provides intake not lower than 1220 kcal/day for normal adults and ensures a proper blend of foods to meet nutritional requirements. (Note: this requirement may not be

appropriate for children, older individuals, and athletes).

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Recommendations

2. Includes foods acceptable to the dieter in terms of socio-cultural background, usual habits, taste, costs, and ease in acquisition and preparation.

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Recommendations

3. Provides a negative caloric balance (not to exceed 500 to 1000 kcal/day), resulting in gradual weight loss without metabolic derangement, such as ketosis.

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Recommendations

4. Results in a maximal weight loss of 1 kg/week.

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Recommendations

5. Includes the use of behavior modification techniques to identify and eliminate diet habits that contribute to malnutrition.

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Recommendations

6. Includes an exercise program that promotes a daily caloric expenditure of 300 or more kcal.

For many participants, this may be best accomplished with low intensity, long duration exercise, such as walking.

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Recommendations

7. Provides that new eating and physical activity habits can be continued for life in order to maintain the achieved lower body weight.

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Caution

In designing the exercise component of a weight loss program, the balance between intensity and duration of exercise should be manipulated to promote a high total caloric expenditure (300 to 500 kcal per session and 1000 to 2000 kcal per week for adults).

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Caution

Obese individuals are at an increased relative risk for orthopedic injury, and this may require that the intensity recommended for improvement of cardiorespiratory endurance.

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Caution

Non-weight bearing activities (and/or rotation of exercise modalities) may be necessary and frequent modifications in frequency and duration may also be required.

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Setting Goals

A healthy body weight is based on the client’s present FFM and % BF goal.