Chapter 9 Flashcards
Eating disorders
- characterized by persistent disturbance in eating behaviors
- focus in course on anorexia nervosa, bulimia nervosa, and binge-eating disorder
- see slides for graph comparing the 3
Anorexia Nervosa
- term means “lack of appetite induced by nervousness” (not true!)
- relentless pursuit of thinness leading to significantly low body weight
- 2 types: restricting type and binge-eating/purge type
DSM5 Criteria for Anorexia Nervosa
A: restriction of energy intake leading to significantly low body weight
B: intense fear of gaining weight
C: disturbances in way weight/shape is experienced (perception issue)
Gull and eating disorders
- first person to describe treatment of someone with anorexia
Bulimia Nervosa
- uncontrollable binge eating and efforts to prevent resulting weight gain (vomiting/exercise)
- comes from Greek words bous (ox) and limos (hunger)
- similar to binge-eating/purging type of anorexia (distinguish between them based on weight – here are normal or slightly above normal rate)
- might have as much as 4,800 calories in binge
- behaviors both occur avg. 1x/week for 3 months
Binge-eating disorder
- like bulimia but without inappropriate compensatory behavior
- less dietary restraint (not thinking ab losing weight)
- associated w being overweight or obese
- binging occurs avg. 1x/week for 3 months
- more likely to have overvalued ideas ab importance of weight/shape vs overweight/obese ppl w/o BED
Age of onset and gender differences (eating disorders)
- anorexia nervosa most likely to develop in 16-20yo
- bulimia nervosa most likely in women 21-24
- binge-eating more common between 30 and 50
- 3x more women than men w eating disorder
Prevalence of eating disorders
Binge-eating disorder
- most common form
- lifetime prevalence 2% worldwide (3.5% in women and 2% in men in US)
- prevalence higher in obese people (6.5-8%)
Bulimia
- worldwide prevalence est. 1%
- lifetime prevalence in US about 1.5% in women and 0.5% in men
Anorexia
- lifetime prevalence in US 0.9% in women and 0.3% in men (similar to Sweden)
- risk of developing anorexia increased in 20th century, risk for bulimia has gone down in last decade
- many young people have body image issues
Medical Complications in Anorexia Nervosa
- mortality rate over 5x higher than for females 15-34
- 3% of ppl with anorexia nervosa die
- malnutrition takes toll on body
- thiamin deficiency can lead to depression and cognitive changes
- laxative abuse can lead to dehydration, kidney disease, damage to bowels/intestines
Medical Complications in Bulimia Nervosa
- mortality rate ab 2x higher than comparable groups
- calluses on hands from sticking fingers down throat
- damage teeth bc of acidity of vomit (mouth ulcers and cavities)
- often small red dots around eyes caused by pressure of throwing up
Course and outcome of Anorexia Nervosa
- suicide 2nd highest cause of death after complications
- 18x more likely to die by suicide
- possible to become well again even after series of treatment failures
- can still have food issues when they have become ‘well’
Course and outcome of Bulimia Nervosa
- long-term prognosis quite good, high rates of remission
- can still have food issues when they have become ‘well’
- suicide attempts in 25-30% of cases
Course and outcome of binge-eating disorder
- high rates of clinical remission
Diagnostic crossover of eating disorders
- some eds so similar that there is debate about if they should be diagnosed as distinct disorders
- when someone has been diagnosed w an eating disorder they are more likely to later be diagnosed w another ed
- bidirectional transitions between two types of anorexia is common
- shift from anorexia to bulimia in 1/3 of patients in study
- binge-eating and anorexia are very different
Comorbidities of eating disorders
- 68% of patients w anorexia, 63% w bulimia, and 50% w BED are also diagnosed w depression
- OCD often found in ppl w anorexia and bulimia
- 2/3 of sample of anorexic patients were rigid and perfectionistic even as children
- often comorbid personality disorders
- binging/purging disorders associated w substance abuse disorders
- more than 1/3 of patients w eds have engaged in SH
- BED: high rates of anxiety disorders (65%), mood disorders (46%), and substance abuse disorders (23%)
Eating disorders across cultures
- not culture-bound; increased prevalence w exposure to Western ideals
- white ppl have more subclinical problems that may put them at higher risk for developing EDs
- study in Fiji; ideal was being fat but changed after tv was introduced, women started dieting
- bulimia nervosa is pretty bound to western culture
Genetics and eating disorders
- anorexia: risk for relatives 11.4x higher
- bulimia: risk for relatives 3.7x higher
- association w genes linked to psychological (schizophrenia, neuroticism) and metabolic (ie diabetes) problems
Area of brain linked to body image perception
temporal cortex
Serotonin + Dopamine in eating disorders
- serotonin involved in modulating appetite and feeding behaviors; implicated in obsessionality/mood disorders
- new research centers on reward pathways/neurotransmitters (dopamine!)
- theory that normally rewarding stimuli (food) becomes aversive bc reward/punishment systems get contaminated
Family influences and eating disorders
- family dysfunction not more prevalent in those w eds
- influence is belief oriented (ie parent focus on thinness)
- anorexia: rigidity, parental overprotectiveness, excessive control, marital discord
- bulimia: high parental expectations, perceiving family as less cohesive, other members who are dieting/concerned ab weight or make critical comments ab weight/eating
- disordered eating attitudes may predate parent-child conflict/family dysfunction
Gender/Age Differences in eating disorders
- women more at risk (esp for anorexia/bulimia)
- adolescence is greatest risk period
- for men, sexual orientation is risk factor
- in binge-eating onset is later and more common in men
Psychological Factors in eating disorders
- internalizing the thin ideal
- perfectionism (may help maintain bulimic pathology, more common in women, may have genetic basis)
- negative body image (often bc sociocultural pressure)
- dieting (risk factor for dev. or worsening)
- negative emotionality (food behaviors can be a strategy to reduce negative affect)
- gay/bisexual men are more at risk
Treatment of Anorexia Nervosa
- generally pessimistic ab potential of recovery
- high therapy dropout rate
- immediate concern to restore weight to non-life-threatening level
- aggressive treatment efforts can backfire (eg hospitalization puts them around other anorexia patients, they want to be even thinner)
- antidepressants may be used, no evidence for effectiveness
- antipsychotic med olanzapine may be beneficial
- family therapy pretty effective in adolescents (Maudsley Model, 6-12 months, work with family to change behaviors relating to feeding, works on relationships)
- CBT has limited success (very effective in bulimia!)
Treatment of Bulimia Nervosa
- use of antidepressants is common
- goal to decrease frequency of binges, improve mood/preoccupation w shape/weight
- CBT is leading treatment (better than meds)
- behavioral component (meal planning, nutritional education, ending binge-purging cycles) and cognitive element (changing cognitions that perpetuate cycle)
Treatment of Binge-Eating Disorder
- antidepressants sometimes used (high comorbidity)
- appetite suppressants and anticonvulsants also used
- for racial/ethnic minorities interpersonal psychotherapy might work best
BMI
- body mass index
- measure of weight relative to height
- obesity defined on having BMI above 30 (morbid obesity is BMI over 40/100lbs overweight)
- BMI of 25-29.9 is overweight
Prevalence and medical issues of obesity
- more prevalent in ethnic minorities (except asians)
- more prevalent in men (except in Black population)
- increased risk for high cholesterol, hypertension, heart disease, arthritis, diabetes, and cancer
- reduced life expectancy of 5 to 20 years
- less than 1/3 US population at normal/healthy weight
US Obesity prevalence by race/ethnicity
- highest in Black women (56.9%)
- 45.7% of Hispanic women, 39% of Hispanic men
- lowest in Asian men and women
BMI equation
weight (lb)/[height (in)]squared X 703 = BMI
Healthy BMI range
18.5-24.9
Overweight BMI range
25-29.9
Obese BMI range
30-39.9
Morbidly obese BMI range
40+
Distribution of obesity in US
- greatest problem in south east US
- lowest rates in Colorado and Massacheusets
- cultural factors play big role, seen as major health crisis in US
Genetics and obesity
- thinness seems to run in family
- genetic mutation associated w binge eating found in only 5% of obese population (only 14% of obese ppl without gene have issues w binge eating)
- BMI likely polygenic
- groups historically more susceptible to starvation are more at risk for obesity when living sedentary lifestyle
Hormones in Appetite and Weight Regulation
- leptin (hormone) acts to reduce intake of food
- inability to produce leptin linked to morbid obesity
- overweight ppl tend to have high levels of leptin but are resistant to effects
- ghrelin has opposite effect
Prader-Willi Syndrome
- chromosomal abnormalities lead to high levels of ghrelin
- sufferers are extremely obese and often die of obesity-related causes before age 30
- food often has to be locked away to avoid binging
Set points
- bodies have tendency to resist variation from biologically determined ‘set point’ or weight that individual bodies try to ‘defend’
- we can only lose or gain a certain amount of weight before body starts resisting a lot
Sociocultural influences in obesity
- culture w access to high-fat, high-sugar foods encourages overconsumption, makes it easy to avoid exercise
- leads to more weight-related problems
- explains higher numbers in low SES bc ‘junk’ food is often cheaper
Family influences in obesity
- family attitudes are important!
- if someone close to us becomes obese, risk of us becoming obese increases by as much as 57%
Stress and comfort food
- when we are stressed/anxious we are conditioned to eat comfort food
- eating in response to these events is reinforced bc food tastes good and emotional tension is reduced
- lifetime rates of mood disorders higher in obese pop.
Treatment of obesity
- many dimensions!
- low calorie diet, exercise, behavioral intervention
- weight watchers has demonstrated efficacy
- ‘crash’ diets and extreme treatments ineffective
- bariatric surgery is most effective long-term treatment (stomach size is reduced to reduce food intake – wright loss avg 44-88 pounds)
- meds have limited benefits
Prevention of obesity
- need to work on what food is available to ppl (esp in schools)
- Hill et al. 2003 argue that ppl can avoid weight gain by eating 3 less bites at every meal, taking the stairs, and sleeping more