Chapter 6 Notes

Chapter 6 Maintaining a Healthy Weight

Principles of Personal Health

I. Body Image and Self-Concept

A. The media tells people that being overweight is undesirable because it does not conform to the ideal body image

B. Ideal body image- Our perception of how our body appears

C. Little media attention has been paid to being underweight

II. Defining Overweight and Obesity

A. Overweight and obesity may be caused by consuming more calories than are expended

B. Overweight- Excessive weight against a given standard

C. Obesity- Excessive body FAT (greater than 30%)

D. The key to losing weight is to eat healthful and exercise regularly

III. Determining Weight and Body Composition

A. Height/Weight Tables

1. No longer considered the best way to determine whether body weight is acceptable (Body composition is not included)

B. Healthy Body Weight

1. Waist-to-hip ratio

a. Measure around your waist

b. Measure around your hips

c. Divide the waist measurement by the hip measurement

2. Weight loss should occur no faster than ½ to 1 pound per week

3. Protruding stomach and high blood indicate a need to lose weight

4. The "spare time" pattern is most frequently seen in men

5. Women more often have excessive weight in the hips & legs

C. Body Mass Index

1. Indicates the relationship of body weight to height

2. Does not reflect body composition

D. Electrical Impedance

1. Measures an electrical impulse sent through the body

2. Adipose tissue resists the electrical current more than does non-fat tissue

3. This process is painless but expensive

E. Skinfold Measurements

1. Precise indicator of body fat percentage

2. Pressure calipers are used to measure the thickness of the layer of fat beneath the skin’s surface (subcutaneous fat)

3. Measurements are taken at several sites on the body

F. Hydrostatic Weighing

1. Precise method for determining amounts of fat and lean body mass

2. Compares underwater body weight with the weight of the body out of the water

3. Impractical for the average person (Expensive)

G. Appearance

1. Look in the mirror

2. This is fairly accurate and inexpensive

3. For some people it can be difficult to be objective

IV. Origins of Obesity

A. Obesity is a complex condition caused by a variety of factors:

1. Genetic Basis of Obesity

a. Both environment and genetics influence obesity

b. The distribution of body fat is strongly influenced by genetic factors

2. Appetite Center

a. Researchers have identified centers for the control of eating:

· The feeding center for hunger

· The satiety center for fullness

3. Set Point Theory

a. Theory suggests that centers of the body possess a genetically programmed awareness of the body’s desirable weight

b. Set point- A genetically programmed range of body weight

c. The body adjusts the metabolic rate upward or downward to accommodate calorie intake or expenditure

d. Lost weight is regained to a level above that of the initial set point

4. Body Type

a. Ectomorphic body type- A tall slender body that protects individuals from excessive weight

b. Mesomorph- Shorter, more heavily muscled body which has a greater difficulty with obesity during adulthood

c. Endomorphs- Body types that tend to be round and soft with excessively large abdomens

5. Infant and Adult Eating Patterns

a. Batriatricians- Physicians who specialize in the study and treatment of obesity

b. Hypercellular obesity involves infant feeding - The number of fat cells a person has is determined during the first two years of life

c. Hypertrophic obesity is related to a long-term positive calorie balance - over a period of years fat cells increase in size

6. Externality

a. Many obese people have highly developed levels of sensitivity to the outside world

b. Eating behavior may be controlled by external stimuli

7. Endocrine Influence

a. No more than 3% to 5% of obesity is a result of hypothyroidism

8. Pregnancy

a. During the normal pregnancy, a woman will develop nine extra pounds of adipose tissue

b. The typical woman enters childbirth having gained about 28 pounds

c. Ideally, after the birth, the mother will have a weight gain of only two to three pounds

d. Many women experience an overall decrease in weight after pregnancy

9. Decreasing Basal Metabolic Rate

a. The body’s requirement for energy decreases with age

b. This alters the ratio of lean body tissue to fat

10. Family Dietary Practices

a. The family instructs children on many topics: information, values and skills

b. Food preferences & dietary practices are among these

c. Snacking on unhealthful foods, large serving sizes, multiple servings and high-calorie meals can lead to obesity

11. Inactivity

a. The single most important reason so much obesity exists

b. Automation, watching television, and a dislike of exercising are reasons that account for inactivity

V. Caloric Balance

A. Any calories consumed and not used by the body are converted to fat

B. Weight gain - When energy input exceeds energy output

C. Weight loss - When energy output exceeds energy input

D. Weight Maintenance - Energy output and input are identical

VI. Energy Needs of the Body

A. Energy needs are based on three factors:

1. Activity Requirements

a. Vary directly according to the amount of daily physical work

b. You must examine the total amount of activity to estimate your caloric requirements

2. Basal Metabolism

a. Uses the highest proportion (50% to 70%) of total calories

b. Basal Metabolic Rate (BMR)- The amount of energy the body requires to main basic functions

c. The body expends calories even when sleeping

d. BMR gradually declines with age

e. The most important variables related to BMR are aging, body composition, activity level, and caloric intake

3. Thermic Effect of Food

a. Energy our bodies require for the digestion, absorption, and transportation of food

b. Represents about 10% of our total energy needs

VII. Lifetime Weight Control

A. Keys to success in weight control:

1. Exercise (cardiovascular and weight training exercises)

2. Dietary modification

3. Lifestyle support (build a support group that will encourage you)

4. Problem solving (Replace any reliance on food as a coping mechanism)

5. Redefinition of health

VIII. Weight Management Techniques

A. Weight loss followed by weight gain may be less healthful than maintaining body weight

B. Approaches to weight loss:

1. Dietary Alterations

a. The most common approach to weight loss

b. Dieting alone rarely results in long-term weight loss

2. Balanced Diets Supported by Portion Control

a. Establish a nutritionally sound balanced diet that controls portions

3. Fad Diets

a. These approaches are both ineffective and potentially dangerous

4. Low-Calorie Foods and Controlled Serving Sizes

a. A variety of foods have been developed in a reduced-calorie form

5. Controlled Fasting

a. Patients are sometimes placed on a complete fast in a hospital setting

b. Are maintained on only water, electrolytes, and vitamins

c. Unsupervised fasting can be dangerous

d. Nutrient-dense food supplementation products (Ensure, Slimfast) should not be used as meal replacements

6. Self-Help Weight Reduction Programs

a. Commercial weight reduction programs feature a format consisting of:

· A well-balanced diet emphasizing portion control

· Realistic weight loss goals

· Encouragement form supportive individuals

· An emphasis on regular physical activity

· A weight management program

b. Effectiveness is very limited

c. These programs are costly, especially when the program markets its own food products

d. Americans spend $32 billion a year in the quest for thinness ($11.4 billion on diet soft drinks alone)

7. Physical Intervention

a. In an attempt to lose the desire to eat, medications are being used

b. These medications are dangerous for some people

8. Surgical Measures

a. A portion of the small intestine may be bypassed to decrease the body’s ability to absorb nutrients

b. Gastroplasty- Sealing off about half of the stomach with surgical staples

c. Liposuction- Physician inserts a tube through the skin and vacuums away adipose tissue

9. Acupuncture

a. Acupuncture- The insertion of needles into the body to alter electroenergy fields and cure disease

b. Acupuncture is being used as a treatment for obesity

10. Behavior Change Strategies

a. Behavior modification

b. aversive conditioning

c. hypnosis

IX. Weight Management: A Lifelong, Lifestyle-Based Approach

A. Nearly 50% of American adults are attempting to loose weight through dieting

B. Few are able to maintain their weight loss

C. Yo-yo syndrome- The tendency to lose weight, end up heavier, and attempt to diet again

D. Suggested approach to weight management:

1. A varied, balanced approach to eating

2. Reasonable short-term weight loss goals

3. A well planned aerobic fitness component

4. The family should serve as a source of encouragement

X. Physical Activity

A. The most important component of a weight-loss program

B. BMR elevation after moderate exercise lasts two or three hours

C. More fat is lost than through dieting alone

XI. Eating Disorders (Most eating disorders begin with dieting)

A. Anorexia Nervosa

1. Self-induced starvation - The normal body image is lost

2. Treated with psychological intervention with medical and dietary support

3. Prevalence has been low in men but is increasing

B. Bulimia Nervosa

1. A pattern of excessive eating followed by purging

2. Purging is done by vomiting or using laxatives

3. Purging may take the form of extensive exercising or the use of diuretics

4. May be indicated to others by inconsistency between high food intake and weight loss

C. Binge Eating- Consuming large amounts of food in a short time

D. Compulsive Exercise and Compulsive Eating

1. A person may exercise several times daily for up to 6 hours

2. This may be done to offset the effects of compulsive eating

E. Treatment for Eating Disorders

1. Treatment involves the cooperation of several health care providers

2. Components of treatment may include:

a. Behavior modification

b. psychotherapy

c. Nutritional counseling

3. Treatment for bulimia involves individual, family, and nutritional counseling

XII. Underweight

A. Underweight- The lack of adequate body weight

B. To be successful in gaining weight, one must take in more calories than is burnt

C. Increase the intake of calorie-dense foods and curtail excessive physical activity (not to the point that cardiovascular conditioning declines)

XIII. A Final Thought about Health and Weight Management

A. Develop every dimension of health, not simply the physical dimension

B. Self-esteem, respect for your feeling and beliefs may offset the absence of the perfect body image

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