Eating Disorders and Obesity (Chapter 9)

Anorexia Nervosa

• pursuit of thinness that is relentless and involves behaviours that result in a significantly low body weight

Rats and Starvation

• one study found that rats (especially females) that are hungry had less anxiety

  • staying hungry can be a way to control some type of anxiety

Two Types of Anorexia

• restricting type — every effort is made to limit the quantity of food consumed

• binge-eating/purging type — some restriction but mainly eat a lot and then purge it

Bulimia Nervosa

• uncontrollable binge-eating and effort to prevent resulting weight gain by using inappropriate behaviours

• clinical picture is similar to the binge-eating/purging type of anorexia

Two Types of Bulimia

• purging — use laxitives/throw up to prevent weight gain

• non-purging — increase exercise to prevent weight gain

Clinical Aspects of Eating Disorders

• people with anorexia and bulimia share a common preoccupation with their shape and weight

• during an average binge, someone with bulimia nervosa may consume as many as 4800 calories

  • afterwards they will vomit, fast, exercise excessively, or abuse laxatives

• people with bulimia nervosa are often preoccupied with shame, guilt and self-deprecation, and efforts at concealment

Binge-Eating Disorder

• has some clinical features in common with bulimia nervosa, but people with BED do not engage in inappropriate “compensatory” behaviours

• much less dietary restraint in BED

• associated with being overweight or obese

Age of Onset for Anorexia Nervosa

• 16-20

Age of Onset for Bulimia

• 21-24

Age of Onset for Binge Eating

• 30-60

Gender Differences in Eating Disorders

• recent estimates suggest that there are 3 females for every 1 male with an eating disorder

• on established risk factor for eating disorders in men is homosexuality

Prevalence of Binge Eating Disorder

• most common form of eating disorder

• worldwide lifetime prevalence is around 2.21%

• lifetime prevalence is around 2.7% in females and 1.7% in males

• prevalence is higher in obese people (6.5 - 8%)

• many young people — particularly adolescent girls and young adult women — show some evidence of disturbed eating patterns or have distorted self-perceptions about their bodies

Rates of Anorexia in Sexual Minorities

• 1.71%

Rates of Bulimia Nervosa in Sexual Minorities

• 1.25%

Rates of Binge-Eating in Sexual Minorities

• 2.17%

Percentages of Girls and Boys with Body Image Problems

• 41.5% of girls

• 24.9% of boys

Medical Complications of Anorexia Nervosa

• mortality rate is more than 5x higher than that for young females ages 15-34 in the general US population

• effects the whole body

Anorexia Nervosa — Effects on Brain and Nerves

• can’t think right

• fear of gaining weight

• sad

• moody

• irritable

• bad memory

• fainting

• changes in brain chemistry

Anorexia Nervosa — Effects on Heart

• low blood pressure

• slow heart rate

• fluttering of the heart (palpitations)

• heart failure

Anorexia Nervosa — Effects on Hormones

• period stops

• bone loss

• problems growing

• trouble getting pregnant

• if pregnant — at higher risk for

  • miscarriage

  • having a c-section

  • baby with low birth weight

  • postpartum depression

Anorexia Nervosa — Effects on Hair

• thinning

• brittle

Anorexia Nervosa — Effects on Blood

• anemia

• other blood problems

Anorexia Nervosa — Effects on Muscles and Joints

• weak muscles

• swollen joints

• fractures

• osteoporosis

Anorexia Nervosa — Effects on Kidneys

• kidney stones

• kidney failure

Anorexia Nervosa — Effects on Body Fluids

• low potassium

• low magnesium

• low sodium

Anorexia Nervosa — Effects on Intestines

• constipation

• bloating

Anorexia Nervosa — Effects on Skin

• bruise easily

• dry skin

• growth of fine hair all over body

• get cold easily

• yellow skin

• brittle nails

Medical Complications of Bulimia Nervosa

• mortality rate = 2x

• electrolyte imbalances and low potassium (risk of heart abnormalities)

• ipecac syrup, a poison that causes vomiting, can damage the heart muscle

• patients usually develop calluses on their hands from sticking them down their throats

  • tears to the throat can also occur

• because the contents of the stomach are acidic, patients damage their teeth when they throw up repeatedly

• mouth ulcers and dental cavities are a common consequence of repeated purging

• small red dots around the eyes, caused by the pressure of throwing up

  • swollen parotid (salivary) glands, caused by repeated vomiting (“puffy cheeks” or “chipmunk cheeks”)

Course and Outcome of Eating Disorders

• anorexic individuals are 18x more likely to die by suicide than comparably aged women in the general population

• even after a series of treatment failures, it is still possible for women with anorexia nervosa to become well again

• long-term prognosis for bulimia nervosa tends to be quite good, with high rates of remission

  • patients with binge-eating disorder also have high rates of clinical remission

• even when “well”, many individuals who recover from anorexia and bulimia still harbour residual food issues

Diagnostic Crossover in Eating Disorders

• diagnostic crossover is common in eating disorders with transitions between the two subtypes of anorexia nervosa being very common

• transitions from the binge-eating/purging subtype of anorexia nervosa to bulimia nervosa also often occur

Association of Eating Disorders with Other Forms of Psychopathology

• 70% of patients with an eating disorder will report another comorbid problem

• anxiety disorders are most common followed by mood disorders, self-harm, and substance abuse

• obsessive-compulsive disorder often found in patients with anorexia nervosa and bulimia nervosa

• comorbid personality disorders are frequently diagnosed in people with eating disorders

  • Cluster C disorders are associated with both anorexia nervosa and bulimia nervosa

  • Cluster B disorders are more typically associated with bulimia nervosa

  • Personality disorders are similarly reported in around 30% of patients with BED

Genetic Risk Factors for Eating Disorders

• the risk of anorexia for relatives is 11.4x greater than for the relatives of normal controls

• the risk of bulimia for relatives is 3.7x higher than for the relatives of healthy controls

• studies suggest anorexia nervosa and bulimia nervosa are heritable disorders

  • recent genome-wide association study found focus for anorexia nervosa

Brain Abnormalities — Risk Factors in EDs

• one brain area that plays an important role in eating is the hypothalamus

  • internal control mechanism (automatic control like hunger)

Set Points — Biological Risk Factors in EDs

• our bodies have well-established tendency to resist variation from some sort of biologically determined set point or weight that our individual bodies try to defend

Biological Risk Factors for EDs — Serotonin

• implicated in:

  • obsessionallity

  • mood disorders

  • impulsivity

  • modulation of appetite and feeding behaviour (higher serotonin promotes eating)

• active area of research

Reward Sensitivity — Biological Risk Factors for EDs

• theory that reward and punishment systems get contaminated:

  • normally rewarding stimuli such as food become aversive

  • stimuli associated with self-starvation become valued

Sociocultural Risk Factors for EDs

• media such as Vogue and Cosmopolitan exert a great deal of influence in defining the culture’s “ideal body shape” and creating pressures to be thin

• social pressures toward thinness may be particularly powerful in higher socioeconomic status background

• disordered eating attitudes may predate parent-child conflict

Sociocultural Factors — Anorexia Family Characteristics

• rigidity

• parental overprotectiveness

• excessive control

• marital discord

Sociocultural Factors — Bulimic Family Characteristics

• high parental expectations

• perceiving one’s family to be less cohesive

• other family members who are dieting, preoccupied with appearance, or prone to make critical comments about shape/weight

Individual Risk Factors — Gender, Gender Identity and Sexual Orientation

• being female is a strong risk factor for developing eating disorders, particularly anorexia nervosa and bulimia nervosa

• individuals with a marginalized gender or sexual orientation identity are at increased risk

• internalizing thin idea associated with body dissatisfaction, dieting, and negative affect

• self-objectification is linked to disordered eating

• perfectionism is pursuit of unattainably high standards combined with intolerance of mistakes

  • may help maintain bulimic pathology through the rigid adherence to dieting that then drives the binge/purge cycle

  • predates disordered eating in those with anorexia nervosa

  • also have a genetic basis

Individual Risk Factors — Body Dissatisfaction

• sociocultural pressure to be thin

• risk factor for development or worsening of eating disorders

Individual Risk Factors — Negative Emotionality

• causal risk factor for body dissatisfaction

• may also maintain binge eating

• predicts dietary restraint in anorexia nervosa

Treatment of Anorexia Nervosa

• patients often have little motivation to engage in treatment

• high dropout rate from therapy

• immediate concern is to restore weight

Treatment of Anorexia — Medications

• the antipsychotic medication olanzapine may be benficial

Treatment of Anorexia — Family Therapy

• most effective treatment option for adolescent patients

  • best-studied approach: Maudsley Model

• randomized controlled trials show that patients treated with family therapy for 1 year do better than control group

Maudsley Model

• typical treatment program includes 10-20 sessions over 6-12 months

• parents as a support team

  • focus on developing healthier relationships

Treatment of EDs — Cognitive Behaviour Therapy

• very effective in treating bulimia nervosa

• limited success in treating anorexia nervosa

Treatment of Bulimia — Medications

• use of antidepressants (anti-anxiety) is common

• goal = decrease frequency of binges, improve mood, and decreases preoccupation with shape and weight

Treatment of Bulimia — Cognitive-Behavioural Therapy

• leading treatment for Bulimia; superior to medications

  • “Behavioural” = meal planning, nutritional education, ending binging-and-purging cycles

  • “Cognitive” = changing the cognitions and behaviours that initiate or perpetuate a binge cycle

• new development: transdiagnostic approach to treatment and CBT-E

Treatment of Binge-Eating Disorder

• due to the high level of comorbidity with depression, antidepressant medications are sometimes used to treat the disorder

• appetite suppressants and anticonvulsant medications are also used

• studies suggest that for racial ethnic minorities with BED, interpersonal psychotherapy might work best

BMI and Obesity

• body mass index (BMI) is a measure of a person’s weight relative to height

• obesity is defined on the basis of having a BMI above 30

Overweight (BMI)

• 25.0-29.9

Ideal Weight (BMI)

• 19.0-25.0

Obesity — Medical Issues and Prevalence

• increased risk for high cholesterol, hypertension, heart disease, arthritis, diabetes, and cancer

• reduced life expectancy of 6-14 years

• more prevalent in ethnic minorities (except Asians)

• more prevalent in males than in females

Obesity — Weight Stigma

• judgement and discrimination from others

• weight discrimination is increasing; media is a powerful source

  • perpetuates weight-based stereotypes

  • often depicts overweight or obese people in a negative light

• weight bias is seen against women who are obese

• bias is also seen among healthcare professionals

Obesity and the DSM

• obesity is not an eating disorder in DSM-5-TR

• some view obesity as a food addiction

• the idea the neuroadaptations in the dopamine system plays a key role in obesity is still a relatively new idea

The Role of Genes in Obesity

• thinness seems to run in the family

• genetic mutation associated with binge-eating is found in only 5% of the obese population

  • all obese people with the gene reported problems with binge eating

  • only 14% of obese people without the genetic mutation had a pattern of binge eating

• evidence suggests that BMI is polygenic and likely influenced by a large number of common genes

Hormones Involved in Appetite and Weight Regulation

• Leptin

  • inability to produce leptin is associated with morbid obesity

  • overweight individuals tend to have high levels of leptin, but are resistant to it’s effects

• Ghrelin

  • in Prader-Willi syndrome, chromosomal abnormalities lead to high levels of ghrelin and extreme obesity

Sociocultural Influences on Obesity

• diathesis-stress perspective is most appropriate

• North America = perfect storm

  • artificial combination of high fat and high sugar contributes to addictive-like eating

  • foods with low nutritional value (high fat, high sugar) are also less expensive and much easier to find than foods with high nutritional value

  • food advertising triggers automatic and unconscious eating

Family Influences on Obesity

• family attitudes toward food — their consequences are likely to remain with us for a long time

  • high-fat, high-calorie diet (or an overemphasis on food) may lead to obesity in family members

  • eating (or overeating) may be used as a way to alleviate emotional distress or show love

  • overfeeding infants and young children causes them to develop more adipose (fat) cells and predisposes them to weight problems

• if someone close to us becomes obese, chances that we become obese increases by as much as 57%

Stress and “Comfort Food”

• when under stress, people and animals eat foods high in fat or carbohydrates

• weight gain may be explained in terms of learning principles

  • we are all conditioned to eat in response to a wide range of environmental stimuli

  • anxiety, anger, boredom, and depression may lead to overeating

  • eating in response to such cues is then reinforced because the taste of good food is pleasurable and emotional tension is reduced

Pathways to Obesity

• combination of genetic, environmental, and sociocultural influences

• binge eating is a predictor of later obesity

• binge eating may be caused by:

  • social pressure to conform to the thin ideal, which leads to dieting followed by binge eating when willpower runs out

  • depression, low self-esteem, and peer rejection

Treatment of Obesity — Lifestyle Modifications

• a first step — a low calorie diet, exercise, and some form of behavioural intervention

• among popular diets, a study found Atkins diet lost the most weight

• weight watchers — only commercial weight-loss program with efficacy in RCT

• “crash” diets and extreme treatments are outmoded and ineffective approaches

Treatments of Obesity — Medications

• several medications are approved by the FDS for use in conjunction with a reduced-calorie diet

  • orlistat (xenical)

  • lorcaserin (belviq)

  • contrave

  • semagultide (wegovy)/ozempic/mounjaro

• only modest effects

Treatment of Obesity — Bariatric Surgery

• most effective long-term treatment for mobidly obese

• reduces food consumed at any time (reduction of stomach size)

• weight loss averaging between 44 and 88 pounds