Download Chapter 8: Achieving a Healthy Weight

Achieving a Health Weight
and Body Composition
Chapter 8
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Achieving a Healthy Weight
At any given time, more than one-half of women
and one-fourth of men are on a diet
 For some people the weight obsession can lead
to serious body-image problems, including body
dysmorphic disorder (BDD)
 The number of people who would benefit from a
weight-loss program is at an all-time high
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Healthy Aspects of Obesity
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Coronary heart
disease
Stroke
Hypertension
LDL cholesterol
Diabetes
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Psychological
distress
Gallbladder
disease
Osteoarthritis
Sleep apnea
Some cancers
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Obesity Trends Among U.S. Adults
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Development of Obesity
Obesity occurs when the 30 to 40 million adipose
(fat) cells in the body increase in size
(hypertrophy), number (hyperplasia), or both
 Gender differences in fat storage

– Males- upper half of body (android)
– Females- lower half of body (gynoid)
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Biological factors that influence obesity are age,
metabolism, gender, disease, heredity, and set
point
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Adipose Cell Deposits
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Causes of Obesity

Heredity influences both body weight
and body shape
– Ectomorph
– Endomorph
– Mesomorph
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The set point theory suggests that
the body works to maintain a certain
weight no matter what a person
does
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Overeating
consuming more calories than are required by the body
Most experts view high dietary
fat intake as the major factor
in obesity
 Calories from fat appear to
convert to body fat more
readily than calories from
carbohydrates and protein
 Portion size
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Overeating and Inactivity
People cannot eat as much as they
want to just because a food is fat
free
 Modern conveniences and laborsaving devices have resulted in less
physical activity
 A sedentary lifestyle is partially
responsible for the obesity in
America
 Physical exercise is vital for weight
maintenance
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Inactivity
Some experts view lack of physical activity as
the distinguishing factor that separates the
obese from those of normal weight
 Exercise alone is not a major component in
weight loss, but it is the most important
component in weight gain
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Strategies for Weight
Management or Weight Loss
The loss of one pound of body fat requires a
deficit of 3500 calories
 A desirable long-term goal for losing weight is 1 to
2 pounds a week until 10% of total body weight is
lost
 A six-month maintenance program should follow
weight loss before losing more
 Weight loss should be a combination of restricting
calories and increasing caloric expenditure

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Strategies for Weight
Management or Weight Loss (2)

Dieting
– the method of choice for most
people to lose weight
– Only 5% of dieters successfully
lose and maintain their weight
loss for one year
– Weight cycling (yo-yo dieting)
usually results in a greater
weight gain following a loss
period and increases the risk of
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death
Strategies for Weight
Management or Weight Loss (3)
Caloric intake should not drop below 1200 per
day for women or 1500 per day for men
 Popular Diets
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– Potentially hazardous
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Characteristics of fad diets
– Promote quick results; focus on eating one type of
food or excluding an entire food group, rarely
emphasize permanent lifestyle changes
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Strategies for Weight Management
or Weight Loss (4)

Low fat diets
– Americans are consuming fewer fat calories but more
total calories and are getting heavier
Very low calorie diets (VLCDs) have fewer than
800 calories a day and should be viewed as
medical intervention
 Americans are consuming fewer fat calories but
more total calories and are getting heavier

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Strategies for Weight
Management or Weight Loss (5)
Overcompensatory eating is when the
consumption of low-fat foods leads to
an increase in total calories
 Increases in portion sizes of foods in
restaurants and in the grocery
contribute to greater food consumption
 Diet drugs offer only a temporary
solution and side effects can be deadly
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Strategies for Weight
Management or Weight Loss (6)
Herbal remedies are unregulated and
when taken in large, concentrated
doses should be viewed as drugs
 The optimal approach to weight loss
combines mild caloric restriction with
regular physical activity
 Fasting and modified fasts can be
harmful especially if done for a
prolonged period of time
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Mayo Clinic
Healthy Weight Pyramid
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Physical Activity
Physical activity and dieting should yield a
daily caloric deficit of 300 to 1000 calories
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Physical Activity
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Basal metabolic rate (BMR) is the energy
required to sustain life when the body is
rested and fasting
Persons who are deconditioned need to start
slowly and progress gradually
Increased muscle tissue raises BMR
People who lose weight and keep it off almost
always exercise daily
Low intensity exercise burns more fat calories
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Guidelines
To reduce risk of chronic diseases in
adulthood: 30min of moderate physical
activity daily
 To prevent unhealthy weight gain in
adulthood: 60min of moderate to vigorous
physical activity on most days
 To sustain weight loss in adulthood: 60min
moderate daily physical activity
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Eating Disorders
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Anorexia nervosa
– the refusal to maintain minimally normal weight for age and height.
– characterized by the refusal to eat
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Bulimia nervosa
– alternates bingeing with purging (Symptoms of disordered eating are
also serious
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Binge-eating disorder
– Consuming large amounts of food in one sitting
– Lack of control
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The Female Athlete Triad is common among young athletes
– Disordered eating, amenorrhea, osteoporosis
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Principles of Weight Management

They include:
Avoiding an obsession
with body weight
 Avoiding fad diets
 Avoiding fasting and
restrictive dieting
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Developing a plan
 Being physically active
 Making gradual
lifestyle changes
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Achieving a Health Weight and Body
Composition
Chapter 8
© McGraw-Hill Companies. All rights reserved.