AP Syllabus focus:
‘Feeding and eating disorders involve altered food consumption or absorption that impairs health or functioning; AP Psychology focuses on anorexia nervosa and bulimia nervosa, with biological, genetic, social, cultural, behavioral, or cognitive causes.’
Feeding and eating disorders reflect disrupted patterns of eating and weight-related thinking that harm physical health and psychological functioning. AP Psychology emphasises recognising core features of anorexia nervosa and bulimia nervosa and explaining their multifactorial causes.
Core idea: impaired eating and health
Feeding and eating disorders involve altered food consumption (how much/when/how) and sometimes absorption, leading to clinically significant impairment. Common psychological themes include:
Overevaluation of weight/shape in self-worth
Body dissatisfaction and distorted self-perception
Cycles of restriction, loss of control, and/or compensatory behaviours
Key disorders in AP Psychology
This infographic contrasts several eating disorders, including anorexia nervosa and bulimia nervosa, using short, plain-language descriptions. It’s useful for quickly distinguishing restriction-focused patterns (anorexia) from binge–compensate patterns (bulimia) at a glance. Source
Anorexia nervosa
Anorexia nervosa: An eating disorder marked by persistent energy intake restriction, intense fear of gaining weight, and disturbed body image, resulting in significantly low body weight.
This BMI chart shows how body mass index varies by height and weight, with labeled ranges such as underweight and normal. It can help you connect the diagnostic idea of “significantly low body weight” in anorexia nervosa to a standardized screening metric (while remembering BMI is only one piece of clinical assessment). Source
Typical features include:
Restrictive eating (often with rigid “rules” about food)
Intense fear of weight gain, even when underweight
Body image disturbance (perceiving oneself as larger than reality)
Possible excessive exercise to control weight
Health and functioning risks (conceptual level):
Malnutrition and fatigue; impaired concentration
Endocrine and cardiovascular strain (e.g., low energy availability)
Increased vulnerability to medical complications as restriction persists
Bulimia nervosa
Bulimia is defined by binge–purge or binge–compensate cycles rather than sustained low weight.
Bulimia nervosa: An eating disorder involving recurrent binge eating (a sense of loss of control) followed by compensatory behaviours (e.g., vomiting, laxatives, fasting, excessive exercise) to prevent weight gain.
Common features include:
Binge eating episodes: unusually large amounts of food with loss of control
Compensatory behaviours to “undo” calories
Shame, secrecy, and self-criticism that can maintain the cycle
Weight may be average or above average, which can delay recognition
Health and functioning risks (conceptual level):
Electrolyte imbalance risk due to purging
Gastrointestinal and dental problems linked to vomiting
Fluctuating mood and anxiety around eating and body evaluation
Explanations and causes (multifactorial)
This diagram highlights three broad contributors to eating-disorder risk—biological, psychological, and social factors—reinforcing the idea that no single cause explains anorexia or bulimia. Use it as a visual organizer before adding more specific examples (genetics, learning, cognition, and culture). Source
AP Psychology emphasises that anorexia and bulimia can arise from interacting biological, genetic, social, cultural, behavioural, and cognitive factors.
Biological and genetic factors
Genetic predisposition: heritable vulnerability to disordered eating and related traits (e.g., anxiety, perfectionism)
Brain and hormone regulation differences that may affect appetite, reward sensitivity, and stress responsivity
Temperamental traits (partly biological), such as high harm avoidance or rigidity, can increase risk
Social and cultural factors
Cultural ideals that glorify thinness and stigmatise larger bodies
Social comparison amplified by peers and media exposure
Activities emphasising leanness (certain sports/dance) may increase pressure
Family and peer dynamics (e.g., comments about weight) can act as triggers or maintainers
Behavioural learning factors
Operant conditioning: dieting/weight loss may be reinforced by praise or a sense of control
Negative reinforcement: purging or restriction can reduce anxiety/guilt temporarily, strengthening the behaviour
Habit formation: repeated binge–purge cycles can become automatic coping responses to distress
Cognitive factors
Cognitive distortions (all-or-nothing thinking: “I ate one cookie, I’ve failed”)
Attentional bias toward weight/shape cues and perceived “flaws”
Overvaluation of body shape/weight as the primary source of self-esteem
In bulimia, “what-the-hell effect” thinking can escalate a small lapse into a binge
FAQ
Yes. Compensatory behaviours can include fasting or excessive exercise, not only self-induced vomiting.
Purging can disrupt sodium/potassium balance, increasing risk of weakness and cardiac rhythm problems.
Thin-ideal internalisation plus frequent social comparison can increase body dissatisfaction, dieting, and escalating control behaviours.
Perfectionism can intensify rigid food rules and self-criticism, making restriction feel like “success” and lapses feel intolerable.
Short-term relief (reduced anxiety/guilt) and reinforced identity/control can outweigh long-term risks, especially under stress.
Practice Questions
Outline two differences between anorexia nervosa and bulimia nervosa. (3 marks)
1 mark: Anorexia involves persistent restriction leading to significantly low body weight; bulimia involves recurrent binge eating.
1 mark: Bulimia includes compensatory behaviours (e.g., vomiting/laxatives); anorexia is primarily restriction (may include excessive exercise).
1 mark: Bulimia weight may be average; anorexia typically underweight (credit any clear, accurate distinction).
Explain how behavioural and cognitive factors could maintain bulimia nervosa. (6 marks)
Up to 3 marks (behavioural): negative reinforcement (purging reduces anxiety/guilt); operant reinforcement (sense of control); cycle becomes habitual through repetition.
Up to 3 marks (cognitive): all-or-nothing thinking after dietary lapse; overvaluation of weight/shape; maladaptive self-talk/shame increasing binge likelihood.
