Chapter 15: Weight Management and Disordered Eating

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Chapter 15 Weight Management and Disordered
Eating
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The Status of Obesity in America

• In the early 1960s, fewer than 32 of Americans
  were overweight
• Today, 67 of Americans are overweight
• More than 33 of adults and 16 of children are
  obese
• Americans spend over 45 billion annually on
  weight-loss solutions
• Medical complications associated with overweight
  cost the U.S. health care system 92 billion
  annually

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What Is Weight Management and Why Is It Important?

• Weight management is maintaining body weight in a
  healthy range
• BMI 18.524.9
• Underweight and overweight can both be of concern

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What Is Weight Management and Why Is It Important?

• Underweight increases risk for
• Low body protein and fat stores
• Depressed immune system
• Overweight and obesity
• Can increase risk of numerous health problems
• Can expose individuals to increased social,
  educational, and economic disadvantages
• Healthy People 2010 aims to reduce overweight and
  obesity in adults to less than 15 and to 5 in
  children and adolescents

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Quick Review

• Weight management means maintaining a healthy
  weight (BMI 18.524.9) to reduce risk of certain
  health problems
• Both underweight and overweight are associated
  with increased health risks
• Obesity and underweight are associated with
  negative social and psychological effects
  including discrimination, low self-esteem,
  depression, suicide, and alcohol and drug
  problems
• Reducing overweight and obesity are two of the
  Healthy People 2010 national health objectives

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How Do Fat Cells Form and Expand?

• Growth of fat cells (adipocytes) occur in two
  ways
• Can expand to store more fat (hypertrophy)
• Once filled to capacity, stimulate the production
  of more fat cells (hyperplasia)

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How Do Fat Cells Form and Expand?

• Average adult has 3050 billion adipocytes which
  hold 0.40.5 micrograms of fat each
• Adipocytes of obese individuals store 0.61.2
  micrograms of fat per cell
• Weight loss leads to shrinking the size of
  adipocytes, but no change in the number of cells
• Hyperplasia slows with age, but growth and
  production of fat cells continues throughout life

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The Formation of Adipocytes
Figure 15.1
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How Do Fat Cells Form and Expand?

• Enzymes control the size of fat cells
• Lipoprotein lipase (LPL) increases lipogenesis
• Hormone-sensitive lipase (HSL) stimulates
  lipolysis
• Heavier people have increased activity of LPL
• Men LPL more active in visceral, abdominal fat
  cells
• Women LPL activity higher in hips and thighs

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Quick Review

• The average adult body contains 3050 billion
  adipocytes
• When adipocytes reach their maximum capacity to
  store fat, new cells form
• Obese individuals have more fat cells storing a
  greater quantity of fat
• LPL and hormone-sensitive lipase are enzymes that
  influence the balance between lipogenesis and
  lipolysis
• The activity of these enzymes differs in overfat
  and lean individuals and in men and women

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How Is Food Intake Regulated?

• Hunger and satiation are controlled by hormones
  that are produced in the brain and
  gastrointestinal tract
• Appetite is the desire to eat food whether or not
  there is physical hunger may be triggered by
  factors such as time of day, social occasions,
  emotions, or the sight or smell of food

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How Is Food Intake Regulated?

• Two regions within the hypothalamusof the brain
  control hunger and satiety
• Ventromedial nucleus
• Lateral hypothalamus

Figure 15.2
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How Is Food Intake Regulated?

• After a meal, satiety is triggered in the
  ventromedial nucleus
• Stretch receptors in the stomach signal fullness
• Cholecystokinin and peptide YY send feedback to
  the hypothalamus to increase satiety and decrease
  hunger
• Nutrient absorption triggers insulin release
  which also decreases hunger
• Leptin, produced by adipose tissue, both
  suppresses hunger and promotes energy expenditure

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How Is Food Intake Regulated?

• The lateral hypothalamus controls hunger
• Ghrelin, produced by the stomach, stimulates
  hunger during fasting or on a low-kilocalorie
  diet
• Neuropeptide Y is produced in the hypothalamus
  and activated by ghrelin it stimulates hunger
  and LPL activity
• In addition to hormones, certain macronutrients,
  especially protein, promote satiety and reduce
  food intake

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Quick Review

• Food intake is controlled by hunger, satiety, and
  appetite
• Within the brain, the ventromedial nucleus
  controls satiety and the lateral hypothalamus
  controls hunger
• Neuropeptides, hormones, and neural signals from
  the gastrointestinal tract and adipocytes
  communicate hunger and satiety to the
  hypothalamus
• Leptin and ghrelin play key roles in triggering
  hunger and satiety, with ghrelin triggering
  hunger and leptin triggering satiation

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Genetics in Obesity and Weight Management

• Genetics can make the body more susceptible to
  weight gain or weight loss
• Genetic differences in the level or functioning
  of some hormones such as leptin and ghrelin
• Differing responses to environment and
  availability of food
• Different rates of nonexercise activity
  thermogenesis (NEAT)
• Genetic set point theory that individuals have
  a genetically established body weight and
  deviation from this point will stimulate changes
  in metabolism to reestablish the normal weight

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Environment in Obesity and Weight Management

• Environmental factors can increase appetite and
  decrease physical activity
• Gene-environment interaction the interaction of
  genes and the environment increases risk of
  obesity in susceptible individuals
• Lack of time results in Americans turning to
  high-calorie convenience foods or dining out
• An abundant food supply and portion distortion
  result in people eating more
• Decreased physical activity and increased
  sedentary behavior means Americans are burning
  fewer calories

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Quick Review

• Genetic influences play a role in weight
  management including influencing the levels of
  the hormones leptin and ghrelin
• Environmental factors, including lack of time, an
  abundant food supply, portion distortion, and
  lack of physical activity, encourage obesity

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How Can You Lose Weight Healthfully?

• Overweight individuals should aim to lose 10 of
  their body weight over 6 months
• The keys to long-term weight management

Figure 15.3
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The Volume of Food
Figure 15.5
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How Can You Lose Weight Healthfully?

• Devote 60 to 90 minutes daily to
  moderate-intensity physical activity to aid in
  weight loss, prevent weight gain

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Quick Review

• The keys to successful long-term weight loss
  include reducing daily kilocalorie intake,
  increasing physical activity, and changing
  behaviors
• Meals of low-energy density, high-volume
  vegetables, fruits, and fiber along with lean
  protein and healthy oils promote satiety and
  reduce unplanned snacking
• Daily physical activity facilitates weight loss
• Changing unhealthy habits by removing certain
  environmental cues supports healthy eating habits

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How Can Weight Loss Be Maintained?

• Setting realistic weight goals is essential to
  prevent false hope syndrome and risk of dropping
  a weight-loss program
• Weight cycling is thought to lead to problems
  such as hypertension, gallbladder disease, and
  elevated cholesterol
• After weight loss, a person will have lower
  energy needs because there is less body weight to
  maintain this is known as the energy gap
  phenomenon
• Increasing daily physical activity is the easiest
  way to close the energy gap and overcome weight
  loss plateaus
• Some individuals with a BMI gt 40 are candidates
  for extreme treatments to lose weight

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Extreme Measures for Extreme Obesity

• A very low-kilocalorie diet
• Is a short-term solution for individuals at high
  risk of disease related to obesity
• Requires vitamin and mineral supplementation and
  medical supervision
• Weight-loss medications
• Sibutramine (Meredia) suppresses appetite
• Orlistat (Xenical) inhibits fat absorption

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Extreme Measures for Extreme Obesity

• Surgery
• Gastric bypass
• Gastric banding
• Liposuction

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Quick Review

• Setting realistic weight-loss goals will prevent
  the false hope syndrome associated with trying to
  achieve goal weight too quickly
• Exercise improves muscle mass, prevents a decline
  in basal metabolism, and helps overcome weight
  loss plateaus
• Eating less or exercising more helps close the
  energy gap following weight loss
• For individuals with a BMI greater than 40, more
  extreme weight loss treatments may be indicated

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What Is the Healthiest Way to Gain Weight?

• Eat sufficient energy to meet basal needs plus
  fuel for the exercise needed to stimulate muscle
  synthesis
• Focus on a variety of energy-dense, nutritious
  food choices
• Eat larger portions at meals and energy-dense
  snacks during the day
• Add at least 500 kilocalories daily for weight
  gain of about one pound per week
• Regular exercise and resistance training
  stimulate muscle growth and help to avoid excess
  fat storage

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More- and Less-Energy-Dense Food Choices
Figure 15.7
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Quick Review

• Weight gain can be as challenging and frustrating
  as trying to lose weight
• People who want to gain weight need to consume
  additional kilocalories through energy-dense food
  to take in more energy than they expend
• Increasing portion sizes and adding
  nutrient-dense snacks helps to increase total
  intake
• Add resistance exercise to build muscle mass

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What Is Disordered Eating?

• Disordered eating describes abnormal and
  potentially harmful eating patterns
• Eating disorders are psychological illnesses
  diagnosed by meeting specific criteria that
  include disordered eating behaviors and other
  factors
• Eating disorders affect over 1 million U.S.
  individuals

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Health Consequences of Disordered Eating

• Health consequences of anorexia nervosa include
• Electrolyte imbalances
• Drop in heart rate and blood pressure, weakness
  and fatigue, hair loss
• Slowing of the digestive process
• Inadequate nutrient intake and possible
  deficiencies

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Health Consequences of Disordered Eating

• Health consequences of bulimia nervosa include
• Tears in the esophagus
• Tooth decay and gum disease from stomach acid
• Electrolyte imbalances
• Dehydration and constipation
• Impaired normal bowel function through laxative
  use

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Eating Disorders Not Otherwise Specified

• Binge eating disorder
• Characterized by recurrent episodes of binge
  eating without regard to physiological cues
• May eat for emotional reasons resulting in
  out-of-control feeling while eating and physical
  and psychological discomfort after eating
• May eat in secret and feel ashamed about their
  behavior
• Negative health effects are those associated with
  obesity such as high blood pressure, high
  cholesterol, heart disease, type 2 diabetes, and
  gallbladder disease

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Eating Disorders Not Otherwise Specified

• Night eating syndrome
• A person consumes a majority of daily
  kilocalories after the evening meal and wakes up
  during the night to eat
• Typically does not have an appetite during
  morning hours
• Is a unique combination of disordered eating, a
  sleep disorder, and a mood disorder
• Stress is a contributing factor to the
  development and continuation of the disorder
• May feel guilty, ashamed, or embarrassed while
  eating at night as well as the next morning
• Most often in young adults 1830 years old

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How Are Eating Disorders Treated?

• Effective treatment requires a multidisciplinary
  team approach including
• Psychological professionals
• Medical professionals
• Nutrition professionals
• As some eating disorders can be life-threatening,
  a physician should closely monitor treatment

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How Are Eating Disorders Treated?

• A Registered Dietitian can help someone with an
  eating disorder establish normal eating behaviors
• Nutritional approaches include
• Meal planning
• Using food journals
• Identifying binge triggers, safe and unsafe foods
• Recognizing hunger and fullness cues
• Full recovery from eating disorders is possible
  and most successful when the disorder is treated
  in the early stages

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Quick Review

• Disordered eating is characterized by an abnormal
  eating pattern
• Eating disorders include disordered eating and
  other diagnostic criteria
• Over 11 million Americans struggle with eating
  disorders
• Eating disorders include anorexia nervosa,
  bulimia nervosa, binge eating or compulsive
  overeating, and night eating syndrome
• Recovery is possible, particularly if treatment
  is sought in the early stages of the disorder

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Putting It All Together

• Maintaining a healthy body weight reduces the
  negative physical and psychological effects of
  obesity
• Hunger and satiety are regulated by the
  hypothalamus of the brain through neuropeptides,
  hormones, and neural signals from the
  gastrointestinal tract and adipocytes
• Both genetic and environmental factors influence
  obesity and weight management
• Diet, physical activity, behavior modification
  are the keys to long-term weight management
• Eating disorders include anorexia nervosa,
  bulimia nervosa, binge eating or compulsive
  overeating, and night eating syndrome
• Treatment of eating disorders requires a
  multidisciplinary team approach