Feeding & Eating Disorders (College Board AP® Psychology): Revision Note

Symptoms of feeding & eating disorders

• Feeding and eating disorders are characterized persistent disturbances in eating behavior that impair physical health or psychological functioning

  • These disturbances go beyond normal variations in diet or food preferences and are among the most medically serious psychological disorders, as they have relatively high mortality rates

• Two disorders include:

  • anorexia nervosa

  • bulimia nervosa

Anorexia nervosa

• Anorexia nervosa is characterized by:

  • restriction of energy intake as the person severely limits the amount they eat

    • This leads to significantly low body weight

  • intense fear of gaining weight even when already significantly underweight

  • distorted body image, which is an inaccurate perception of body size

    • They may deny the seriousness of their low body weight

      • E.g. a person who is dangerously underweight but perceives themselves as overweight and continues to restrict food intake

• There are two presentations of anorexia:

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

    • There is no binge eating or purging

  • Binge-eating/purging type: weight loss through restriction but also accompanied by episodes of binge eating followed by purging

• Medical consequences of anorexia are severe and can be life-threatening. They include:

  • malnutrition

  • electrolyte imbalances

  • cardiac arrhythmias

  • bone density loss (osteoporosis)

  • amenorrhea (cessation of menstruation)

  • organ failure and death in extreme cases

• Anorexia nervosa has the highest mortality rate of any psychological disorder

• It predominantly affects young women, though it is increasingly recognized in males and across age groups

Bulimia nervosa

• Bulimia nervosa is characterized by:

  • recurrent binge eating, where the individual eats a large amount of food in a with a sense of lack of control over eating during the episode

  • compensatory behaviors to prevent weight gain following a binge:

    • Purging type: self-induced vomiting; misuse of laxatives, diuretics, or enemas

    • Non-purging type: fasting or excessive exercise

  • overevaluation of body weight and shape where the person's self-worth is strongly tied to their appearance

    • E.g. a person who frequently binges and then purges, experiencing shame but feeling unable to stop the cycle

• Bulimia shares similar features with anorexia (preoccupation with weight and body image) but differs in that:

  • people with bulimia are often within the normal weight range, making the disorder less visible

  • the binge-purge cycle is the defining behavioral pattern

• Medical consequences of bulimia include:

  • dental erosion from stomach acid (frequent vomiting)

  • electrolyte imbalances

  • esophageal damage

  • swollen salivary glands

  • cardiac complications from electrolyte disturbances

Causes of feeding & eating disorders

• Feeding and eating disorders are best explained by interacting biological, psychological, behavioral, and sociocultural factors

Biological and genetic factors

• Genetic factors: both anorexia and bulimia are heritable

  • They run in families and twin studies show higher concordance in identical twins

• Neurochemical factors: both eating disorders are linked to serotonin dysregulation

  • Serotonin affects mood, appetite, and impulse control

• Personality traits: genetic predisposition to perfectionism, anxiety, and obsessiveness, particularly in anorexia

Psychological factors

• Cognitive distortions: distorted body image (seeing oneself as larger than one is) and overvaluation of thinness as a measure of self-worth are central cognitive features of eating disorders

• Perfectionism and low self-esteem: eating disorder behaviors are often attempts to gain control and meet unrealistic standards

• Emotional regulation: binge eating can function as a way of managing negative emotions

  • The temporary relief from emotional distress negatively reinforces the bingeing behavior

Behavioral factors

• Dieting as a trigger: Restriction can initiate disordered eating, particularly in genetically vulnerable individuals

• Negative reinforcement (anorexia): avoidance of feared foods is negatively reinforced (reduces anxiety), maintaining restrictive eating patterns

• Negative reinforcement (bulimia): the binge-purge cycle in bulimia is maintained as the purge temporarily relieves the guilt and physical discomfort of the binge

Social and cultural factors

• Cultural ideals of thinness: eating disorders are significantly more prevalent in cultures with strong sociocultural pressure to be thin

  • Western cultures particularly equate thinness with attractiveness, success, and self-control

• Media influence: exposure to idealized body images through media is associated with body dissatisfaction and disordered eating

  • This may explain why eating disorders are increasingly identified globally as Western cultural influences spread