DSM-5 Eating Disorder Categories and Diagnostic Criteria
The DSM-5 consolidated feeding and eating disorders into a single category and now recognizes six main eating disorders: Anorexia Nervosa (AN), Bulimia Nervosa (BN), Binge-Eating Disorder (BED), Avoidant/Restrictive Food Intake Disorder (ARFID), and two residual categories—Other Specified Feeding or Eating Disorder (OSFED) and Unspecified Feeding or Eating Disorder (UFED). 1, 2, 3
Major DSM-5 Changes from DSM-IV
The DSM-5 made substantial revisions to reduce the overuse of the "Not Otherwise Specified" category, which previously captured up to 50-68% of patients seeking treatment 3, 4, 5. These changes improved diagnostic utility and decreased reliance on residual categories from 68% to 53% 5.
Primary Eating Disorder Categories
Anorexia Nervosa (AN)
The DSM-5 modified AN criteria significantly 1, 2:
- Removed the amenorrhea requirement (previously mandatory in DSM-IV)
- Eliminated specific numerical weight thresholds (e.g., 85% of expected body weight)
- Now requires: restriction of energy intake leading to significantly low body weight, intense fear of weight gain, and disturbance in body image
- Maintains two subtypes: restricting type and binge-eating/purging type
Clinical significance: AN carries the highest mortality rate among eating disorders at 5.1 deaths per 1000 person-years—nearly 6 times higher than age-matched controls—with 25% of deaths from suicide 6.
Bulimia Nervosa (BN)
DSM-5 made minor but important changes 2, 3:
- Lowered frequency threshold from twice weekly to once weekly for binge eating and compensatory behaviors
- Reduced minimum duration to 3 months (from 6 months in DSM-IV research criteria)
- Removed severity subtypes (purging vs. non-purging)
- Core features remain: recurrent binge eating, inappropriate compensatory behaviors, and self-evaluation unduly influenced by body shape/weight
BN is associated with a 76.3% lifetime rate of depression 6.
Binge-Eating Disorder (BED)
BED was elevated from a provisional diagnosis to a formal, full-threshold eating disorder 1, 2, 3. This represents one of the most significant DSM-5 changes:
- Requires recurrent binge eating episodes (once weekly for 3 months)
- Marked distress regarding binge eating
- Absence of regular compensatory behaviors (distinguishing it from BN)
- Associated with 65.5% lifetime depression rate 6
Avoidant/Restrictive Food Intake Disorder (ARFID)
ARFID was moved from the childhood feeding disorders section and expanded 2, 3:
- Characterized by food avoidance or restriction not driven by weight/shape concerns
- Results in significant weight loss, nutritional deficiency, dependence on supplements, or psychosocial impairment
- Critical distinction from AN: absence of body image disturbance or fear of weight gain
- Applies across the lifespan, not just children
Other Specified Feeding or Eating Disorder (OSFED)
OSFED replaced "Eating Disorder Not Otherwise Specified" (EDNOS) 3, 7. It includes five specific examples:
- Atypical AN: meets all AN criteria except weight remains in/above normal range despite significant loss
- Sub-threshold BN: meets BN criteria but frequency/duration below threshold
- Sub-threshold BED: meets BED criteria but frequency/duration below threshold
- Purging disorder: recurrent purging without binge eating
- Night eating syndrome: recurrent nighttime eating episodes
Important caveat: OSFED presentations carry similar medical and psychiatric severity as full-threshold disorders and should not be dismissed as less serious 7.
Unspecified Feeding or Eating Disorder (UFED)
Used when clinicians choose not to specify the reason criteria aren't met or insufficient information exists for a more specific diagnosis 3.
Clinical Assessment Framework
When evaluating for eating disorders, the APA guidelines 8 mandate comprehensive assessment including:
- Weight history: maximum/minimum weights, recent changes, BMI (or BMI percentile/Z-score for youth)
- Eating behaviors: restrictive eating patterns, binge episodes, food avoidance, rumination, regurgitation, chewing/spitting
- Compensatory behaviors: purging (vomiting, laxatives), driven exercise, medication misuse
- Cognitive symptoms: percentage of time preoccupied with food/weight/shape, body image disturbance
- Physical examination: vital signs with orthostatic measurements, signs of malnutrition or purging
- Laboratory workup: CBC, comprehensive metabolic panel (electrolytes, liver/renal function)
- ECG: mandatory for restrictive eating disorders, severe purging, or QTc-prolonging medications
Common Diagnostic Pitfalls
Watch for diagnostic drift: patients frequently move between eating disorder categories over time, and OSFED may represent either a distinct condition or a transitional state 7. Always assess for lifetime history of full-threshold disorders, as this impacts prognosis and treatment planning.
Don't minimize OSFED: despite being a residual category, OSFED presentations demonstrate comparable impairment, medical complications, and psychiatric comorbidity to full-threshold disorders 7.
Screen systematically: up to 50% of eating disorder cases were missed under DSM-IV criteria due to overly restrictive thresholds 4. The DSM-5 changes specifically aimed to capture these clinically significant presentations.