Chapter 22: Feeding and Eating Disorders

Feeding and eating disorders represent a diverse group of psychiatric conditions characterized by persistent disturbances in eating patterns that significantly compromise physical health, psychological wellbeing, and social functioning. The DSM-5-TR classification system identifies six primary disorders within this category alongside other specified and unspecified presentations. Anorexia nervosa manifests through severe dietary restriction leading to significantly reduced body weight, coupled with intense fear of weight gain and fundamental disturbances in body perception, with distinct restricting and binge-purging presentations. Bulimia nervosa involves recurrent episodes of uncontrolled eating followed by compensatory behaviors such as self-induced vomiting, laxative misuse, or excessive exercise. Binge eating disorder presents with recurrent binge episodes without the compensatory purging behaviors characteristic of bulimia, making it the most prevalent eating disorder across populations. Avoidant and restrictive food intake disorder differs fundamentally by involving food avoidance unrelated to weight or appearance concerns, often stemming from sensory sensitivities, fear of adverse consequences, or traumatic associations with eating. Pica and rumination disorder represent distinct feeding disturbances involving consumption of non-food substances and regurgitation behaviors respectively. Epidemiological evidence demonstrates pronounced gender differences in anorexia and bulimia prevalence, while binge eating disorder shows more equitable distribution across sexes. Etiology involves complex interactions among genetic vulnerability, developmental factors, personality traits such as perfectionism and impulsivity, sociocultural pressures emphasizing thinness ideals, and neurobiological abnormalities in reward processing and appetite regulation. Medical consequences vary by disorder but encompass cardiovascular complications, electrolyte imbalances, bone density loss, gastrointestinal damage, dental erosion, and metabolic dysfunction. Treatment approaches require comprehensive multidisciplinary coordination integrating medical stabilization, nutritional counseling, psychotherapeutic interventions including cognitive-behavioral therapy and family-based approaches particularly for adolescent presentations, and pharmacological agents such as selective serotonin reuptake inhibitors and lisdexamfetamine in appropriate clinical contexts.