Chapter 9 NUTR

Chapter 9

Weight Management:
Overweight, Obesity, and
Underweight

© 2009 Cengage - Wadsworth

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.


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


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.


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.


Overweight

• Set-Point Theory
The body’s natural regulatory centers
maintain homeostasis at set point.
The human body tends to maintain a
certain weight.


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.


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.


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


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


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.


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.


• 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


• 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


• 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.



• Dangerous Interventions
Fad Diets
• False theories
• Inadequate diets
• Can be a danger to health


• 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.


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.


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.


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.


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.


• 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.


• 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.


• 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.


• 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.


• 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.


• 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.



• 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.



• 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.


Underweight

• Incidences of underweight and
associated health problems are less
prevalent than overweight and
obesity problems.


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.


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.


The Latest and Greatest
Weight-Loss Diet--Again


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.


The Diet’s Appeal

• There are many misconceptions and
distortions of facts.
• Results are not long lasting.


The Diet’s Achievements

• Don’t Count kCalories
• Satisfy Hunger
• Follow a Plan
• Limit Choices


The Diet’s Shortcomings

• Too Much Fat
• Too Much Protein
• Too Little of Everything Else


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


Chapter 9 NUTR

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