1. Significantly low body weight due to restriction of energy intake relative to metabolic needs
2. Body image disturbance
3. Intense fear of gaining weight
   • There is no weight cut off
   • Amenorrhea is not necessary for diagnosis
4. Persistent lack of recognition of the seriousness of the current low body weight

Subtypes

1. Restrictive
2. Purging

Atypical Anorexia

Malnutrition can happen to anyone, regardless of baseline BMI. Patients with higher BMIs who lose a significant amount of weight or who exhibit rapid weight loss may present medically and behaviorally similar to a patient with ‘typical’ anorexia nervosa, however, weight and BMI may be misconstrued as normal on growth curves.

Bulimia Nervosa

Binge eating followed by a compensatory behavior (purging, laxative use, over-exercising, abstaining from food) at least once a week x 3 months

Patient is still at a normal weight or above normal weight.

Avoidant Restrictive Food Intake Disorder (ARFID)

Eating disturbance in kids > 6 years old leading to one of the following:

1. Low weight or growth delay
2. Nutritional deficiency
3. Marked interference with psychosocial functioning

Subtypes:

• Limited interest in food, decreased appetite
• Selective eating due to sensory issues
• Posttraumatic such as fear of eating due to choking episode etc.

See below for more in-depth descriptions of diagnoses.

Anorexia Nervosa: 307.1 (F50.01 or F50.02)

1. Restriction of energy intake relative to requirements leading to significantly low body weight in the context of age, sex, developmental trajectory, and physical health. Significantly low weight is defined as a weight that is less than minimally normal or, for children and adolescents, less than that minimally expected.
2. Intense fear of gaining weight or becoming fat, or persistent behavior that interferes with weight gain, even though at a significantly low weight.
3. Disturbance in the way in which one's body weight or shape is experienced, undue influence of body weight or shape on self-evaluation, or persistent lack of recognition of the seriousness of the current low body weight.

F50.01 Restricting Type

F50.02 Binge Eating/Purging Type

Specify if: In partial remission: After full criteria for anorexia nervosa were previously met, Criterion A has not been met for a sustained period, but either Criterion B or C is still met. In full remission: After full criteria for anorexia nervosa were previously met, none of the criteria have been met for a sustained period.

Specify current severity: The minimum level of severity is based, for adults, on current body mass index (BMI) (see below) or for children and adolescents, on BMI percentile. The ranges below are derived from World Health Organization categories for thinness in adults; for children and adolescents, corresponding BMI percentiles should be used. The level of severity may be increased to reflect clinical symptoms, the degree of functional disability, and the need for supervision. Mild: BMI > 17 kg/m2 Moderate: BMI 16-16.99 kg/m2 Severe: BMI 15-15.99 kg/m2 Extreme: BMI < 15 kg/m2

Avoidant/Restrictive Food Intake Disorder: 307.59 (F50.8)

1. An eating or feeding disturbance (e.g., apparent lack of interest in eating or food; avoidance based on the sensory characteristics of food; concern about aversive consequences of eating) as manifested by persistent failure to meet appropriate nutritional and/or energy needs associated with one (or more) of the following:
   1. Significant weight loss (or failure to achieve expected weight gain or faltering growth in children).
   2. Significant nutritional deficiency.
   3. Dependence on enteral feeding or oral nutritional supplements.
   4. Marked interference with psychosocial functioning.
2. The disturbance is not better explained by a lack of available food or by an associated culturally sanctioned practice.
3. The eating disturbance does not occur exclusively during the course of anorexia nervosa or bulimia nervosa, and there is no evidence of a disturbance in the way in which one’s body weight or shape is experienced.
4. The eating disturbance is not attributable to a concurrent medical condition or not better explained by another mental disorder. When the eating disturbance occurs in the context of another condition or disorder, the severity of the eating disturbance exceeds that routinely associated with the condition or disorder and warrants additional clinical attention.

Other Specified Feeding or Eating Disorder: 307.59 (F50.8)

This category applies to presentation in which symptoms characteristic of a feeding and eating disorder that cause clinically significant distress or impairment in social, occupational, or other important areas of functioning predominate but do not meet the full criteria for any of the disorders in the feeding and eating disorders diagnostic class. The other specified feeding or eating disorder category is used in situations in which the clinician chooses to communicate the specific reason that the presentation does not meet the criteria for any specific feeding and eating disorder. This is done by recording “other specified feeding or eating disorder” followed by the specific reason (e.g., bulimia nervosa of low frequency).

Examples of presentations that can be specified using the "other specified" designation include the following:

1. Atypical anorexia nervosa: All of the criteria for anorexia nervosa are met, except that despite significant weight loss, the individual's weight is within or above the normal range.
2. Bulimia nervosa (of low frequency and/or limited duration): All of the criteria for bulimia nervosa are met, except that the binge eating and inappropriate compensatory behaviors occur, on average, less than once a week and/or for less than 3 months.
3. Binge-eating disorder (of low frequency and/or limited duration): All of the criteria for binge-eating disorder are met, except the binge eating occurs, on average, less than once a week and/or for less than 3 months.
4. Purging Disorder: Recurrent purging behavior to influence weight or shape (e.g., self-induced vomiting, misuse of laxatives, diuretics, or other medications) in the absence of binge eating.
5. Night eating syndrome: Recurrent episodes of night eating, as manifested by eating after awakening from sleep or by excessive food consumption after the evening meal. There is awareness and recall of the eating. Night eating is not better explained by external influences such as changes in the individual's sleep-wake cycle or by local social norms. Night eating causes significant distress and/or impairment in functioning. The disordered pattern of eating is not better explained by binge-eating disorder or another mental disorder, including substance use, and is not attributable to another medical disorder or an effect of medication.

Unspecified Feeding or Eating Disorders: 307.50 (F50.9)

This category applies to presentation in which symptoms characteristic of a feeding and eating disorder that cause clinically significant distress or impairment in social, occupational, or other important areas of functioning predominate but do not meet the full criteria for any of the disorders in the feeding and eating disorders diagnostic class. The unspecified feeding and eating disorder category is used in situations in which the clinician chooses not to specify the reason that the criteria are not met for a specific feeding and eating disorder and includes presentations in which there is insufficient information to make a more specific diagnosis (e.g., in emergency room settings)

Source: American Psychiatric Association: Diagnostic and Statistical Manual of Mental Disorders, 5th Ed.