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Chapter 9 NUTR
- 1. Chapter 9
Weight Management:
Overweight, Obesity, and
Underweight
© 2009 Cengage - Wadsworth
- 2. Overweight
• Overweight (BMI 25-29.9) and
obesity (≥ 30) are widespread health
problems that are continuing to
increase.
• Many refer to overweight and obesity
as an epidemic.
• For good health, weight management
is important.
© 2009 Cengage - Wadsworth
- 4. Overweight
• Fat Cell Development
Fat cell numbers
• Fat cell numbers increase most rapidly in
later childhood and early puberty.
• Fat cell numbers increase in times of
positive energy balance.
• Hyperplastic obesity
© 2009 Cengage - Wadsworth
- 6. Overweight
• Fat Cell Development
Fat cell size
• Fat cell sizes increase when energy
intake exceeds expenditure.
• Hypertrophic obesity
The adverse effects of fat in non-
adipose tissue are called lipotoxicity.
© 2009 Cengage - Wadsworth
- 7. Overweight
• Fat Cell Metabolism
Lipoprotein lipase promotes fat
storage.
Gender differences
• Men are at increased risk for developing
central obesity and women are at
increased risk for lower body fat.
• Enzymes that break down fats affect men
and women differently.
© 2009 Cengage - Wadsworth
- 8. Overweight
• Set-Point Theory
The body’s natural regulatory centers
maintain homeostasis at set point.
The human body tends to maintain a
certain weight.
© 2009 Cengage - Wadsworth
- 9. Causes of Obesity
• Obesity may not be as simple as food
intake exceeding metabolic needs.
• Some factors, such as overeating
and inactivity, are within our control.
• Genetic, hormonal and emotional
factors may require professional
intervention.
© 2009 Cengage - Wadsworth
- 10. Causes of Obesity
• Genetics
Leptin (also called the ob protein)
• Protein that acts as a hormone to
increase energy expenditure and
decrease appetite
• Produced by fat cells under the direction
of the ob gene
• May be deficient in obese individuals
• More research is needed.
© 2009 Cengage - Wadsworth
- 12. Causes of Obesity
• Genetics
Ghrelin
• Protein that acts as a hormone to
decrease energy expenditure and
increase appetite
• Produced by stomach cells
• Has an inverse relationship with PYY
© 2009 Cengage - Wadsworth
- 13. Causes of Obesity
• Genetics
Uncoupling Proteins
• Influence energy metabolism
• White adipose tissue stores fat to be used
for energy.
• Brown adipose tissue stores fat to be
used for heat.
• May oppose the development of obesity
© 2009 Cengage - Wadsworth
- 14. Causes of Obesity
• Environment – The gene pool of our
population remains relatively unchanged.
Overeating
• Present and past eating influences current body
weight.
• Increased availability of convenient food, large
portions, and energy-dense foods
Physical Inactivity
• Modern technology replaces physical activities.
• Physical activity is important to allow people to
eat enough food to get needed nutrients.
© 2009 Cengage - Wadsworth
- 15. Problems with Obesity
• Obesity problems depend on many
factors such as the extent of
overweight, age, health status and
genetic makeup.
• Risk factors may differ among
individuals.
© 2009 Cengage - Wadsworth
- 16. Problems with Obesity
• Health risks are evaluated using BMI, waist
circumference and disease profiles.
Overweight people who are in good health may not
need to lose weight.
Obese or overweight people with risk factors could
improve health by losing weight or using other diet
and exercise strategies. Risk factors include:
• Hypertension
• Cigarette smoking
• High LDL
• Low HDL
• Impaired glucose tolerance
• Family history of heart disease
• Men ≥ 45 years, women ≥ 55 years
© 2009 Cengage - Wadsworth
- 17. Problems with Obesity
• Health Risks
Obese or overweight people with the
following life-threatening-conditions
may improve health by losing weight:
• Heart disease
• Type 2 diabetes
• Sleep apnea
© 2009 Cengage - Wadsworth
- 18. Problems with Obesity
• Perceptions and Prejudices
Social Consequences
• Prejudices and discrimination
• Judged on appearance rather than character
• Stereotyped as lazy and lacking self-control
Psychological Problems
• Feelings of rejection, shame and depression are
common.
• Ineffective treatments can lead to a sense of
failure.
© 2009 Cengage - Wadsworth
- 20. Problems with Obesity
• Dangerous Interventions
Fad Diets
• False theories
• Inadequate diets
• Can be a danger to health
© 2009 Cengage - Wadsworth
- 21. Problems with Obesity
• Dangerous Interventions
Weight-Loss Products
• Ephedrine-containing products inhibit serotonin
and suppress the appetite. Supplements
containing Ephedra have been banned by the FDA
due to potential health risks.
• Herbal laxatives do not prevent absorption.
• Current laws do not require safety tests and
effectiveness tests for these products.
Other Gimmicks
• Don’t work
• There is no such thing as cellulite.
© 2009 Cengage - Wadsworth
- 22. Aggressive Treatments of
Obesity
• Individuals with clinically severe
obesity and major medical problems
may benefit from drugs or bariatric
surgery.
• But changing and improving eating
and exercise habits offer the greatest
benefit.
© 2009 Cengage - Wadsworth
- 23. Aggressive Treatments of
Obesity
• Drugs
Sibutramine suppresses the appetite
and is most effective when used with
a reduced kcalorie diet and increased
physical activity. There are many side
effects.
Orlistat blocks fat digestion and
absorption. There are many side
effects.
Other drugs are still under study.
© 2009 Cengage - Wadsworth
- 24. Aggressive Treatments of
Obesity
• Surgery
Surgery is an option for those who have
tried weight loss programs and failed, have
a BMI ≥ 35, and are having health problems
due to their weight.
Gastric surgery has short-term and long-
term problems and requires compliance
with dietary instructions.
Liposuction is a popular procedure that is
primarily cosmetic but poses risk.
© 2009 Cengage - Wadsworth
- 26. Weight-Loss Strategies
• A life-long eating plan for good
health, which includes nutritionally
adequate eating, reasonable
expectations, regular physical
activity, and permanent lifestyle
changes, is best for achieving
permanent weight loss.
• Weight loss of 1-2 pounds per week
or 10% of body weight in six months
is safe.
© 2009 Cengage - Wadsworth
- 29. Weight-Loss Strategies
• Eating Plans
Be Realistic about Energy Intake
• 300-500 kcalories/day reduction for BMI between
27 and 35
• 500-1000 kcalories/day reduction for BMI ≥ 35
• Dietary Guidelines should be followed.
Diet should be nutritionally adequate while
avoiding excessive consumption.
Smaller portions are recommended to feel
satisfied, not stuffed.
© 2009 Cengage - Wadsworth
- 31. Weight-Loss Strategies
• Eating Plans
Eat foods of lower energy density, that are
high in fiber, high in water and low in fat.
Water is important to increase fullness and
reduce hunger.
Complex carbohydrates offer abundant
vitamins, minerals and fiber with little fat.
Choose fats sensibly and reduce the
quantity of fat.
Watch empty kcalories from sugar and
alcohol.
© 2009 Cengage - Wadsworth
- 33. Weight-Loss Strategies
• Physical Activity
An individual’s body weight as well as intensity and
duration of activity influence energy expenditure.
Physical activity increases the amount of
discretionary kcalories that can be consumed.
Metabolic rates can rise with daily vigorous activity.
Activity can decrease body fat and increase lean
body mass.
Exercise may help to curb appetite.
Activity can reduce stress and improve self-
esteem.
© 2009 Cengage - Wadsworth
- 35. Weight-Loss Strategies
• Physical Activity
Choosing Activities
• Choose activities that you enjoy and are willing to
do regularly.
• Low to moderate intensity for long duration is
recommended.
• Daily routines can incorporate energy activities.
Spot Reducing
• Regular aerobic exercise and weight loss will help
trouble spots.
• Strength training can improve muscle tone.
• Stretching can help flexibility.
© 2009 Cengage - Wadsworth
- 36. Weight-Loss Strategies
• Behavior and Attitude
Behavior modification requires time and
effort.
Awareness of behavior is the first key.
Changing behaviors one at a time works
best.
• Do not grocery shop when hungry.
• Eat slowly.
• Exercise while watching television.
Personal attitudes toward food and eating
must be understood.
Support groups may be helpful for some
people.
© 2009 Cengage - Wadsworth
- 38. Weight-Loss Strategies
• Weight Maintenance
Successful weight-loss maintenance
programs use different criteria so
they are difficult to compare.
Vigorous exercise and careful eating
plans are key.
Frequent self-monitoring is
recommended.
© 2009 Cengage - Wadsworth
- 39. Weight-Loss Strategies
• Prevention
Eat regular meals and limit snacking.
Drink water in place of high-kcalorie
beverages.
Select sensible portion sizes and limit
daily energy intake to energy
expended.
Limit sedentary activities and be
physically active.
© 2009 Cengage - Wadsworth
- 40. Weight-Loss Strategies
• Public health programs have been
suggested to:
Develop safety standards for foods.
Control commercial advertising.
Control conditions under which foods
are sold.
Control prices to reduce consumption.
© 2009 Cengage - Wadsworth
- 41. Underweight
• Incidences of underweight and
associated health problems are less
prevalent than overweight and
obesity problems.
© 2009 Cengage - Wadsworth
- 42. Underweight
• Problems of Underweight
Causes are diverse.
Energy demands may be great and
foods are needed to support growth
and physical activities.
Eating disorders are severe cases.
© 2009 Cengage - Wadsworth
- 43. Underweight
• Weight-Gain Strategies
Energy-dense foods can be included but
choose fat wisely to avoid the associated
cardiac risks.
Regular meals each day must become a
priority.
Use large portions and expect to feel full.
Consume extra snacks between meals.
Juice and milk are easy ways to increase
kcalories.
Exercising to build muscles will support
increases in muscle mass.
© 2009 Cengage - Wadsworth
- 44. The Latest and Greatest
Weight-Loss Diet--Again
© 2009 Cengage - Wadsworth
- 45. The Latest and Greatest
Weight-Loss Diet--Again
• Fad diets do not offer safe or
effective plans for weight loss.
• Diet recommendations should be
research based.
• There are guidelines for identifying
fad diets and weight-loss scams.
© 2009 Cengage - Wadsworth
- 46. The Diet’s Appeal
• There are many misconceptions and
distortions of facts.
• Results are not long lasting.
© 2009 Cengage - Wadsworth
- 47. The Diet’s Achievements
• Don’t Count kCalories
• Satisfy Hunger
• Follow a Plan
• Limit Choices
© 2009 Cengage - Wadsworth
- 49. The Body’s Perspective
• Adverse side effects of low-
carbohydrate, ketogenic diets
Nausea
Fatigue
Constipation
Low blood pressure
Elevated uric acid
Stale, foul taste in the mouth
Fetal harm and stillbirth
© 2009 Cengage - Wadsworth