Eating Disorders

• Worldwide prevalence of eating disorders has been estimated as 7.8%
• Prevalence rates vary between regions in the world (ex: bulimia nervosa was not a major concern in developing countries facing food scarcity)
• Onset of eating disorders typically occurs during adolescence
• Primary characteristic related to anorexia and bulimia nervosa

  An all-encompassing drive to be thin
• Anorexia nervosa has the highest mortality rate of any other psychological disorders
• 20% of people with anorexia nervosa die from this disorder
• 5% of those with anorexia nervosa die after 10 years
• Females living with anorexia nervosa are 18x more likely to die by suicide between the age of 15-34 than the general population
• Bulimia nervosa is one of the most common psychological disorders on university and college campuses
• Behaviours of university/college students with bulimia nervosa

  • 29-34% consistently attempt to limit food intake
  • 14-18% engaged in overeating and binge eating
  • 14-17% combined limiting intake with binge eating
• Average age of onset for bulimia nervosa is around 16
• Binge eating in bulimia nervosa


  Eating a large amount of food (typically high sugar or fat food) in volumes larger than most would consume in the context
• Caloric intake for binges is unique for each person with bulimia nervosa
• Binge eating in bulimia nervosa


  An out-of-control experience
• Compensatory behaviours in bulimia nervosa

  • Self-induced vomiting
  • Fasting
  • Laxatives or diuretics
  • Excessive exercise (57% of people)
• Bulimia nervosa purging type (BNP) involves vomiting, laxatives, diuretics
• People living with BNP experience younger eating disorder onset
• Higher rates of comorbid mental health disorders in BNP

  • Depression
  • Anxiety
  • Alcohol use
  • OCD
• People living with BNP have higher rates of sexual harm at a younger age
• Bulimia nervosa non-purging type (BNNP) occurs in 6-8% of people
• The use of BN subtypes was dropped in the DSM-5
• Purging behaviours are not typically effective for reduction of caloric intake - only approximately 50% of calories are removed when the behaviour is immediate and delayed purging removes even less
• DSM-5 TR criteria for bulimia nervosa

  • Recurrent episodes of binge eating
  • Recurrent inappropriate compensatory behaviors to prevent weight gain
  • Binge eating and inappropriate compensatory behaviours occur, on average, at least once a week for 3 months
  • Self-evaluation is unduly influenced by body shape and weight
  • The disturbance does not occur exclusively during episodes of anorexia nervosa
• Health consequences associated with chronic bulimia nervosa

  • Salivary gland enlargement from repeated vomiting
  • Erosion of dental enamel from repeated vomiting
  • Electrolyte imbalance (sodium & potassium levels)
  • Cardiac arrhythmia
  • Kidney failure
  • Increased body fat for their age
  • Constipation
  • Permanent colon damage from laxative misuse
  • Calluses on finger or back of hands from stimulating the gag reflex
• Most individuals with bulimia are within 10% of their normal body weight, however, drive for thinness and symptoms can persist even 10 years after diagnosis leading to a poor prognosis
• People with bulimia are ashamed of their difficulties and lack of control, so they tend to hide their bulimic symptoms and delay seeking treatment
• Bulimia nervosa is often accompanied by other mental health disorders, most commonly anxiety and mood-related disorders
• Depression tends to occur following the onset of bulimia nervosa
• There is a high prevalence of Borderline Personality Disorder and Non-Suicidal Self-Injury in people with bulimia nervosa
• Co-occurring alcohol use disorder is often present before or after the onset of bulimia nervosa
• Individuals with anorexia nervosa


  Lose weight in considerable amounts that lead to an increased risk for harm
• Anorexia nervosa is characterized by

  A strong fear of gaining weight AND losing control over eating
• People living with anorexia nervosa may be proud of their diets and self-control
• Individuals with anorexia nervosa often do not recognize the potential harms they are facing or the presence of illness, leading to delayed access to support as treatment is often not sought out by people on their own
• The average age of onset for anorexia nervosa is 15
• Many individuals with bulimia nervosa have a history of anorexia nervosa
• Culturally, many of the behaviours associated with anorexia nervosa are praised in social contexts (ex: current fitness or exercise practices, changes to weight)
• Core feature of anorexia nervosa

  An intense fear of weight gain and intense drive for thinness
• Another primary feature of anorexia nervosa


  A marked disturbance in body image, where people with anorexia are likely to overestimate their body weight
• Compensatory behaviours in anorexia nervosa

  • Anorexia Nervosa Restricting Type (ANR) - involves restricting caloric intake
  • Anorexia Nervosa Binge-Eating Purging Type (ANBP) - involves purging