Eating disorders

• Eating disorders


  Severe, psychiatric disorders characterised by a dysfunctional relationship with food and distorted perceptions about the body, that significantly impairs physical health and/or psychosocial functioning
• Eating disorder features - anorexia nervosa


  • Refusal to keep body weight above minimal healthy weight 85%
  • Fear of weight gain
  • Disturbance of body experience
  • Amenorrhea (absence of menstruation)
  • Restriction of intake leading to a significantly low body weight in the context of age, sex, developmental trajectory, and physical health
• Eating disorder features - bulimia nervosa


  • Recurrent episodes of binge eating
  • Compensatory behaviours
  • Bingeing and compensation happen twice per week over at least 3 months
  • Self-evaluation is unduly
• Binge-purge cycle


  1. Strict dieting

  2. Diet slips, or difficult situation arises

  3. Binge eating is triggered

  4. Purging to avoid weight gain

  5. Feelings of shame and disgust
• Binge eating disorder (BED)


  Recurrent episodes of eating significantly more food in a short period of time than most people would eat under similar circumstances, eating very fast in the absence of hunger, marked by feelings of loss of control and guilt, embarrassment, or disgust, bingeing happens once per week over at least 3 months
• Other specified feeding or eating disorder (OSFED)


  • Atypical anorexia nervosa
  • Low frequency bulimia nervosa
  • Low frequency binge eating disorder
  • Purging disorder
  • Night eating syndrome
  • Avoidant/restrictive food intake disorder
• 62% of all people with an eating disorder have symptoms before the age of 16
• All eating disorder features taken from Westernised cultures
• Peak age of onset is slightly younger in anorexia nervosa (14-16 years) instead of 18-20 years
• BED is more common in males than females
• Female to male ratio for eating disorders is 2:1
• Prevalence


  • Anorexia nervosa - 0.5-1% of teenage girls
  • Bulimia nervosa - 1-2% of women aged 16-35
  • BED - 3.6% of women and 2.1% of men
  • OSFED - 2-3% of women aged 16-35
• Incidence


  • Anorexia nervosa - 21 new cases a year per 100,000
  • Bulimia nervosa - 30 new cases per 100,000 population
  • BED - similar to bulimia nervosa but not yet known
• The COVID-19 pandemic led to a 15% increase in eating disorder diagnoses and a 48% increase in hospital admissions for eating disorders
• Eating disorder costs to the NHS are 60% for females under 24 years, £510 per day per inpatient, and outpatient costs are about 40% of inpatient
• Patients with anorexia nervosa have nearly 6 times more chances of dying than people without anorexia nervosa
• Eating disorders are 6th in terms of disability-adjusted life years from early mortality and reduced quality of life for ages 15-24
• Risk factors for eating disorders


  • Female
  • Adolescent/young adult
  • Socio-cultural pressures and expectations (thin ideal)
  • Biological (genetic predisposition, serotonin dysfunction)
  • Family history (depression, substance/alcohol abuse, eating disorder, obesity, chronic dieting)
  • Experiences (parenting, abuse, critical comments, pressures to be slim)
  • Individual characteristics (low self-esteem, perfectionism, anxiety problems, obesity, early menarche)
• Female relatives of anorexia nervosa patients are 11 times more likely to develop anorexia nervosa
• Heritability estimates up to 0.74 for anorexia nervosa, 55% identical twins concordant for anorexia nervosa, much weaker for bulimia nervosa
• Psychodynamic model


  Way of understanding patients' experiences, emphasise meanings attached to symptoms and function of them (e.g. restriction = success/personal effectiveness, vomiting = rid oneself of traumatic sexual experience, hunger = greed), emphasise role of infancy and subsequent experiences in shaping a person, control, avoidance of maturation
• Cognitive behavioural model


  Core behaviours established via positive and negative reinforcement, can include cognitive state
• Family systems


  Family is not the cause, but context in which eating disorder is embedded, symptoms as communicative acts, the homeostatic family, boundaries, conflict avoidance
• Socio-cultural model


  Expression of social values, culture-bound or ethnic disorder, gender role conflicts, identity, representations of beauty through unattainable levels of thinness, evidence of increase in eating disorders when exposed to Westernised ideals
• Sexual abuse is experienced by about 30% of eating disorder patients, may be more significant in men
• Anorexia nervosa treatments


  • Individual CBT-ED (40 sessions over 40 weeks)
  • Maudsley AN treatment (MANTRA, 20 sessions)
  • Specialist supportive clinical management (20 weekly sessions)
  • ED-focused psychodynamic therapy (40 sessions, 40 weeks)
  • AN-focused family therapy for children and young people (20 sessions over 1 year)
• Bulimia nervosa treatments


  • Focused manualised guided self-help (first line of treatment)
  • Individual CBT-ED (20 sessions over 20 weeks, twice weekly sessions in the first instance)
  • BN-focused family therapy for young people (or individual CBT-ED)
• BED treatments


  • BED-focused manualised guided self-help (first line of treatment)
  • Group CBT for EDs (16 weekly sessions over 4 months)
  • Individual CBT (16-20 sessions)
• Remission rates for eating disorders are poor, 12-year follow-up for anorexia nervosa ranges from 13-50% and 30-40% for bulimia nervosa
• If treatment efforts fall during adolescence, those with anorexia nervosa are at risk of "severe and enduring anorexia nervosa"