Eating Disorders

Eating Disorders



DSM Diagnoses and symptoms

Myths about eating disorders:

“Reading” 11: Watch the short clips of leading ED researcher Cynthia Bulik


Biopsychosocial explanation

Supplemental reading: Kaye et al., 2013


Eating disorders:

Group of disorders

Diagnoses in the Diagnostic and Statistical Manual (DSM-5, 2013)

Background information: supplemental info


Eating disorder prevention:

Primary prevention vs. secondary prevention

Traci Mann’s research: (bonus reading)

Early eating disorder prevention programs were not systematically evaluated for efficacy (before this research).

Argues that preventing eating disorders and providing support for those with symptoms require qualitatively different strategies, yet most programs combine primary and secondary prevention.

Informational interventions are not effective

Better to separate primary and secondary prevention interventions

Frequently, episodes of eating disorders are precluded by dieting.

How does this relate to other types of health education and prevention?

Diagnoses in the DSM-5

Feeding and Eating disorders in DSM-5 (2013) and their organization in the previous edition


DSM IV: Disorders first diagnosed in infancy, childhood, or adolescence

Rumination disorder

DSM IV: Disorders first diagnosed in infancy, childhood, or adolescence

Avoidant/restrictive food intake disorder

Feeding disorder of infancy or early childhood

DSM IV: Disorders first diagnosed in infancy, childhood, or adolescence

Anorexia nervosa

Bulimia nervosa

Binge eating disorder

DSM IV: Appendix

Eating Disorders

In recent years, eating disorder research has indicated that these disorders are much more complicated than originally thought.

Also consider subclinical eating disorder symptomatology:

When researchers followed a group of 496 adolescent females for 8 years to age 20, they found:

5.2% met criteria for DSM-5 anorexia, bulimia, or binge-eating disorder

When they included nonspecific eating disorder symptoms, a total of 13.2% suffered from eating disorder by age 20

Prevalence statistics

Eating Disorders

Three commonly described eating disorders are:

Anorexia nervosa:

restriction of caloric intake, underweight

obsession with feeding and/or weight.

Bulimia nervosa: characterized by episodes of overeating, followed by compensatory behavior, such as purging, laxative use, or even intense exercise.

Binge-eating disorder: episodes of significant overeating, followed by distress, disgust, or guilt, but without purging or fasting behavior.

Anorexia nervosa

Greek “anorexia” = loss of appetite

Prevalence: 0.3 – 2 % of population

Approximately 25% of diagnosed cases in males

Anorexia nervosa is an eating disorder in which a person severely restricts eating and shows a preoccupation with weight or food intake

Transition from 1950s perception of disorder in high-achieving women to one that crosses gender, ethnic, geographic and socioeconomic borders

Key symptoms

Persistent energy intake restriction

Intense fear of gaining weight or becoming fat

Disturbed body perception, undue influence of weight or shape on self-evaluation

Anorexia nervosa: DSM criteria

Restriction of energy intake relative to requirements, leading to a significantly low body weight in the context of age, sex, developmental trajectory, and physical health. (weight less than minimally normal or minimally expected)

Intense fear of gaining weight or of becoming fat, or persistent behavior that interferes with weight gain, even though at a significantly low weight.

Disturbance in the way in which one’s body weight or shape is experienced, undue influence of body weight or shape on self-evaluation, or persistent lack of recognition of the seriousness of the current low body weight.


Restricting type: weight loss accomplished primarily through dieting, fasting, and/or excessive exercise

Binge-eating/purging type: recurrent episodes of binge eating or purging behavior (self-induced vomiting, misuse of laxatives, diuretics, or enemas)

Severity: by BMI

Mild: ≥ 17, Moderate: 16-16.99, Severe: 15-15.99, Extreme: < 15

Anorexia nervosa

Fear of obesity, losing control of their shape

Distorted thinking

Low opinion of shape

Overestimate proportions (Farrell, Lee, Shafran, 2005)

Psychological disorders

Depression (71%)

Anxiety (up to 80%)

OCD-like patterns

Anorexia nervosa

In some instances, anorexia is caused by health conditions, rather than psychological disorder.

Infections or diseases

Alzheimer’s disease


Drug abuse – amphetamines or other stimulants


Loss of weight in 50% of cancer patients called wasting

Result from taste sensitivities, treatment, or cancer itself

Taste aversions

Cachexia (Source:

Bulimia nervosa

1 – 3% of the population

90% of cases in females

Bulimia nervosa is an eating disorder in which period of over-eating are followed by compensatory behavior such as purging, use of laxatives, or intense exercise

Different patterns of eating: over-eaters, under-eaters, normal amount of food consumption

Difficult to detect – commonly of normal weight

Key symptoms:

Recurrent episodes of binge eating.

Recurrent inappropriate compensatory behavior in order to prevent weight gain.

Undue influence of weight or shape on self-evaluation

Bulimia nervosa: DSM criteria

Recurrent episodes of binge eating, characterized by:

Eating, in a discrete period of time, an amount of food that is definitely larger than what most individuals would eat in a similar period under similar circumstances.

A sense of lack of control over eating during the episode

Recurrent inappropriate compensatory behavior to prevent weight gain, such as self-induced vomiting; misuse of laxatives, diuretics, or enemas; fasting; or excessive exercise.

The binge eating and compensatory behaviors both occur, on average, at least once a week for three months

Self-evaluation is unduly influenced by body weight and shape.

The disturbance does not occur exclusively during episodes of anorexia nervosa.

Severity: episodes of inappropriate compensatory behavior per week

Mild: 1-3, Moderate: 4-7, Severe: 8-13, Extreme: 14 or more

Bulimia nervosa


1-30 per week

Preceded by feelings of tension

Difficult to control

Elicits feelings of self-blame, shame, guilt, depression, fear

Associated Psychological Disorders

Anxiety in 80% of individuals with bulimia

Mood disorders (depression) co-occur in 20% of patients (typically follows onset of bulimia)

Substance abuse is common

Binge Eating Disorder

DSM-5 criteria:

Recurrent episodes of binge eating

Binge eating episodes are associated with 3 or more of the following:

Unusually rapid eating

Eating large amounts without physical hunger

Eating until uncomfortably full

Eating alone because of embarrassment

Feelings of self-disgust, depression, or severe guilt after episodes

More common than anorexia and bulimia combined: estimates up to 3.5% of population

Health Consequences


Long term damage to bones, osteoporosis

Amenorrhea: decreased fertility

Cardiovascular effects

10-20% fatal (heart or other organ failure)

Bulimia: depends on compensatory behaviors

Vomiting erodes tooth enamel, depletes body of vital salts, harms esophagus, and disrupts muscle, heart, and kidney function

Laxatives destroy bowel muscle and drain salts and fluid from the body

Bingeing/Purging cycle related to irregular menstruation, disrupted bowel habits, and cardiovascular risks

Binge-eating disorder

Health complications of overconsumption and obesity

Type 2 diabetes

“Reading” 11: Nine myths

Reading 11: Nine myths

Watch all (they are only a few minutes each)

You tube link:

Cynthia Bulik – researcher: biographical information

Etiology of Eating Disorders

Etiology: What causes eating disorders?

Biopsychosocial explanation

Biological: brain, neurotransmitters

Psychological: developmental influences, personality and temperament, stress and anxiety

Social: norms, media, culture

Etiology of Eating Disorders

The next four slides are from the Kaye et al., 2013 bonus reading.

Introduction: notable and paradoxical aspects of eating disorders

Narrow range of prevalence (age and gender)

Symptoms: lack of insight to being ill and body image distortions

Ongoing debate on whether the primary symptom related to appetite or other process (e.g. obsessions about body image)


Genetic contributions:

Heredity explains 50-80% of the risk

Thus – what aspects of the disorder are potentially hereditable?

Etiology of Eating Disorders

Temperament and Personality in AN

Comorbid anxiety disorders are common and predictive of more severe eating disorder

Kaye’s research describes an overcontrol in eating, affect, and impulse:

Anhedonia and asceticism

Perfectionism, rigidity, and constrained affect

Harm avoidance: temperament trait to encompass these

Interoception and alexithymia

Brain processes to perceive hunger, taste, and pain may be altered (anterior insula)

Alexithymia: difficulty identifying emotions, satiety / disgust

Etiology of Eating Disorders


Dopamine and serotonin dysfunction: mood and anxiety plus other symptoms

Other neuropeptides vary in the illness phase, but are likely a consequence rather than cause of the disorder

Diagram on next slide to be discussed in class

Altered interoceptive processing of taste and reward (demonstrated by decreased function of reward area of the brain and the insula)

Difficulty differentiating between positive and negative feedback (executive function and…

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