Obesity

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Obesity
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Epidemiology of Obesity

• Definition/Prevalence
• Medical Complications
• Social and Psychological Consequences

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Key Prevalence Facts

• Overall rate of obesity is 34.8
• Rates have risen significantly (25.4 vs 34.8)
• Overall men and women do not differ much (men
  33.7-women 35.9)
• Rates increase with age up to age 64 and then
  decline
• Rates significantly higher among black and
  Hispanic females (see table)

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Epidemiology of Obesity

• Medical complications
• Increases risk for
• Heart disease and stroke
• Certain forms of cancer
• Diabetes
• Contributes to other known risk factors
• Elevated serum cholesterol
• Hypertension
• Physical inactivity

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Epidemiology of Obesity

• Social and psychological consequences
• Social prejudice (more pronounced for women)
• Job discrimination
• Low self-esteem, depression, anxiety

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Epidemiology of Obesity

• Genetics of obesity
• Adoption studies
• Twin studies

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Energy Balance Model of Obesity

• Caloric Intake Caloric Expenditure
• (Weight Gain)
• - (Weight Loss)

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Energy Balance Conceptualization of Obesity

• Calorie input
• Intake of liquid and solid foods
• Calories out
• Basal metabolic rate (BMR)
• Exercise
• Food-related thermogenesis
• Exercise-related thermogenesis

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Assessment of Obesity

• Body weight based on gender and height
• Percent body fat
• Skin-fold thickness
• Underwater weighing
• Electrical impedance
• Body mass index (BMI)

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Medical Treatments for Obesity

• Pharmacotherapy
• Appetite suppressants (Fenfluramine)
• Stimulants (Ephedrine)
• Opiate antagonists (Naltrexone)
• Other medical procedures
• Stomach stapling
• Medically-supervised low calorie
• Liposuction

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Psychological Treatments for Obesity
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Evolution of Behavioral Treatments for Obesity

• First Generation
• Second Generation
• Third Generation

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Cognitive-Behavioral Treatments for Obesity

• Self-monitoring
• Stimulus control
• Goal setting
• Reinforcement
• Education
• Cognitive restructuring
• Nutritional education
• Exercise prescriptions
• Relapse prevention training

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Limitations of Behavioral Treatment Research

• Studies do not last long enough to get patients
  to goal weight
• Inadequate comparison groups
• Inadequate follow-up

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Improving Long-term Weight Loss

• Better screening
• Longer programs
• Incentive systems for increasing adherence
• Social support
• Treatment matching
• Relapse prevention strategies
• Integration of non-behavioral treatments

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Bulimia Nervosa
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Diagnostic Features

• A. Recurrent binge eating
• B. Recurrent inappropriate compensatory behavior
  in order to prevent weight gain
• C. Binge eating and compensatory behavior occur
  at least 2/wk for 3 months
• D. Self-evaluation is unduly influenced by body
  shape and weight
• E. Exclude the diagnosis if the symptoms occur
  exclusively during episodes of anorexia nervosa

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Essential Features of Binge Eating

• Large amount of food consumed in a small amount
  of time (lt 2 hours)
• During the eating episode there is the distinct
  feeling of being out of control over ones eating

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Epidemiology of Bulimia Nervosa

• Prevalence
• 2.8 to 5.5 (Kendler et al, 1991)
• 4 (Rand Kuldau, 1992Whitaker et al, 1990)

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Epidemiology of Bulimia Nervosa

• Etiology
• Genetic factors

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Stice Dual Pathway Model
Pressure to
Dieting
be thin
.17
.38
Body
Bulimic
.14
dissatisfaction
symptoms
.25
.20
Thin-ideal
Negative
internalization
affect
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Risk Factors for Bulimia

• Social pressures to be thin
• Perceived pressure fro thinness is correlated
  with bulimic pathology (Stice et al., 1996)
• Perceived pressure fro thinness predicts future
  bulimic symptoms (Stice et al., 2000)
• Experimental exposure to thin-ideal images
  increases negative affect and body
  dissatisfaction (Stice Shaw, 1994)

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Risk Factors for Bulimia

• Internalization of the thin ideal
• Bulimics are more likely to endorse the thin
  ideal than non-bulimics (Williamson et al, 1993)
• Internalization of the thin ideal is associated
  with bulimic symptoms (Stice et al., 1994)
• Internalization of the thin ideal predicts future
  bulimic symptoms (Kendler et al, 1991 Joiner et
  al., 1997 Stice et al, 2000)

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Risk Factors for Bulimia

• Elevated body fat (adiposity)
• Body Mass Index correlated with bulimic symptoms
  (Stice et al., 1996)
• Body Mass Index predicts future body
  dissatisfaction (Stice et al., 2000)
• Body Mass Index predicts onset of subclinical
  eating pathology (Killen et al., 1994)

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Risk Factors for Bulimia

• Body Dissatisfaction
• High body dissatisfaction is correlated with
  bulimic symptoms (Ruderman Besbeas, 1992)
• Body dissatisfaction predicts future bulimic
  symptoms (Leon et al, 1993 Killen et al., 1994
  Stice et al., 1994)
• Experimentally-induced reduction in body
  dissatisfaction led to decreased binge eating
  relative to baseline (Rosen et al, 1990)

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Risk Factors for Bulimia

• Negative Affectivity
• Bulimics show greater concurrent mood disturbance
  than controls (Ruderman Besbeas, 1992)
• Negative affect predicts future bulimic symptoms
  (Stice et al, 1999)
• Bulimics report more negative affect prior to
  binges than when eating normally (Davis et al,
  1988)
• Experimentally inducing negative affect triggers
  overeating among restrained eaters (Cools et al,
  1992 Telch Agras, 1996)

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Risk Factors for Bulimia

• Dieting (Restrained Eating)
• Bulimics show greater concurrent mood disturbance
  than controls (Ruderman Besbeas, 1992)
• Dieting predicts future bulimic symptoms (Kendler
  et al, 1991)
• Dieting predicts onset of subclinical eating
  pathology (Killen et al., 1994)
• Experimentally-induced caloric deprivation leads
  to disinhibitory eating (Telch Agras, 1996)

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Epidemiology of Bulimia Nervosa

• Associated Conditions (Co-morbidity)
• Alcoholism (3.2)
• Phobias (2.4)
• Depression (2.2)
• Anorexia Nervosa (8.2)
• Borderline Personality Disorder

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Epidemiology of Bulimia Nervosa

• Course

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Pharmacotherapy for Bulimia Nervosa

• Tricyclic Antidepressants

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Pharmacotherapy for Bulimia Nervosa

• Tricyclic Antidepressants
• SSRIs
• d-fenfluramine

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Pharmacotherapy for Bulimia Nervosa

• Tricyclic Antidepressants
• SSRIs
• Fenfluramine
• Phenelzine

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Cognitive Model of Bulimia
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Restraint Theory(Herman Polivy, 1985)

• Major assumptions of the model
• Sociocultural factors leads to dietary restraint
• Dietary restraint increases risk of binge eating
• A variety of factors may operate as disinhibitors
  of restrained eating thus leading to
  counter-regulatory eating (binge eating)
• Cognitive factors play a central role in
  counter-regulatory eating

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Types of Disinhibitors

• Preload
• Alcohol
• Depression
• Anxiety
• Perceived caloric content of a food

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Cognitive-Behavioral Treatments for Bulimia

• Self-monitoring
• Exposure plus response prevention
• Stimulus control/environmental change
• Training in specific coping skills
• Cognitive-restructuring
• Dietary counseling

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Controlled Outcome Studies for Bulimia

• Kirkley et al (1985)
• Fairburn et al (1986)
• Agras et al (1989)
• Fairburn et al (1993 1995)
• Walsh et al (1997)
• Agras et al (2000)

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Agras et al (2000)
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Agras et al (2000)Study Overview

• 220 patients meeting DSM-III-R criteria for
  bulimia nervosa were randomized to CBT or IPT in
  a multisite
• 19 individualized weekly sessions
• Evaluated outcome at posttreatment and at a 12
  month follow-up)
• High attrition (28 CBT vs 24 IPT)

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Agras et al (20000Intent-to-Treat Findings
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Moderators of Treatment Outcome

• Lower weight or Body Mass Index (Wilson et al,
  1986 Agras et al, 1987)
• Self-esteem (Fairburn et al (1987)
• Binge frequency (Garner et al, 1990)
• Personality pathology (Johnson et al, 1990
  Rossiter et al, 1992)
• Naturalistic Investigation of Eating Behavior in
  Bulimia (Davis)

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Binge Eating Disorder
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Diagnostic Features of Binge Eating Disorder

• Recurrent episodes of binge eating
• Perceived loss of control over eating
• Frequency of at least 2/wk for 6 mos.
• Binge eating causes marked distress
• Binge eating does not occur exclusively during
  the course of bulimia nervosa

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Epidemiology of Binge Eating Disorder

• Prevalence

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Associated Features of Binge Eating Disorder

• Elevations on indices of restrained eating
  (McCann et al, 1990)
• Increases with obesity (Telch et al, 1988)
• Elevations on indices of psychological distress
  (Kolotkin et al 1987 Marcus et al, 1988)
• Elevations on indices of depression (Marcus et
  al, 1988)
• Higher lifetime prevalence of major depression
  (Hudson et al 1988)
• Higher prevalence of BPD and panic disorder
  (Yanovski et al (1992)

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CBT for Binge Eating Disorder
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Procedural Components of CBT for Binge Eating
Disorder

• Treatment rationale
• Self-monitoring
• Altering patients meal consumption
• Relapse prevention training

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Controlled Outcome Studies for Binge Eating
Disorder

• Telch et al (1990)
• Wifley et al (1993)
• Agras et al (1994)

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C.Telch et al (1990)
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Wifley et al (1993)
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Agras et al (1993)
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Procedural Components of CBT for Binge Eating
Disorder

• Rationale, Overview or Treatment, Commitment
  Component to attend treatmentAbstinence
• Chain analysis of binge episode (Antecedents and
  consequences of binge and how repair)
• Diary Cards Mood and binge episodes, other side
  skills used
• Reviewing homework
• Didactic/experiential component

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DBT Treatment of Binge Eating Disorder

• DBT Skill Training Areas
• Breathing
• Mindfulness skills
• Emotion regulation skills module
• Distress tolerance skills