Weight Management
• Overweight
• and
• Underweight
Fat Cell Development
Fat Cell Metabolism
• Lipoprotein lipase (LPL) Page 273
• An enzyme that promotes fat storage
by removing fat from the blood and
putting away in adipose tissue.
Obese individuals typically have
more LPL activity.
Set Point Theory
• Based on internal physiological variables,
an individual may be pre-destined to weight
a certain amount in adulthood.
• Research has confirmed that after weight
loss or weight gain, the body will adjust
metabolism to restore the original weight.
Causes of Obesity
• Genetics
–Leptin
–Ghrelin
–PYY
Genetics
• Leptin acts as a hormone in the
hypothalamus. Leptin promotes a negative
energy balance by suppressing appetite and
increasing energy expenditure.
• In Mice, if they have a defective Ob gene
and do not produce enough leptin, they may
have five time the body fat of the average
rat.
Leptin in Humans
• Unfortunately it is extremely rare for
humans to have a genetic deficiency of
leptin. Very few obese people have a leptin
deficiency.
• More research is needed to determine the
impact or role of leptin in energy regulation.
Adiponectin
• A protein made by the fat cells.
• Lean individuals have a higher level.
Ghrelin
• A protein that acts as a hormone by
stimulating appetite and promoting energy
storage.
• Ghrelin triggers the desire to eat.
• Lean individuals have a higher level and
obese individuals a lower level.
• Ghrelin also plays a role in sleep. Lack of
sleep increases ghrelin levels.
PYY
• Signals satiety and decreases food intake.
• A diet low in fat and higher in fiber seems
to stabilize the hormones that have an
effect on appetite.
Causes of Obesity
• Genetics
–Uncoupling proteins
•White body fat
•Brown body fat
Brown Fat
• Most adults have very little brown fat.
• Obese and overweight individuals have less
brown fat than others.
Causes of Obesity
• Environment
–Gene pool
–Overeating
–Physical inactivity
Health Risks
• Overweight in good health
• Obese or overweight with risk
factors
• Obese or overweight with lifethreatening-condition
Dangerous
Interventions
• Fad diets
• Over-the-counter drugs
–Benzocaine
–Phenylpropanolamine
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Dangerous
Interventions
• Other gimmicks
–Cellulite
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Aggressive
Treatments
Of Obesity
• Clinically severe obesity
• Drugs
–Sibutramine
–orlistat
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Surgical Procedures
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Weight-Loss
Strategies
• Eating plans
– Be realistic about energy intake
– Emphasize nutritional adequacy
– Eat small portions
– Lower energy density
– Remember water
– Focus on complex carbohydrates
– Choose fats sensibly
– Watch for empty kcalories
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Energy Density
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Weight-Loss
Strategies
• Physical activity
– Activity and energy expenditure
– Activity and metabolism
– Activity and body composition
– Activity and appetite control
– Activity and psychological benefits
– Choosing activities
– Spot reducing
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Weight-Loss
Strategies
• Behavior and attitude
– Behavior modification
– Become aware of behaviors
– Change behaviors
– Personal attitude
– Support groups
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Underweight
• Problems of underweight
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Eating Disorders
• The female athlete triad
Eating Disorders
• Other dangerous practices of
athletes
–Muscle dysmorphia
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Anorexia Nervosa
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Anorexia Nervosa
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Bulimia Nervosa
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