Francine is a 16-year-old girl with type 1 diabetes diagnosed at age 11, referred by her endocrinologist, Dr. Ward, to Dr. Green, a psychiatrist, for evaluation of “non-compliance”. Dr. Ward explains that Francine had always been “a very good girl,” but over the past several months, her glycemic control has been poor, and she has been noted to be more irritable during her checkups, dismissing his concerns, snapping at her parents, and taking out her phone to check her social media updates. She has also lost 7 lb over 5 months (current height 5′6′′, weight 130 lb, BMI 21). Dr. Ward suspects that she has been taking her insulin erratically, leading to elevated blood sugars and weight loss.

On Dr. Green’s evaluation, Francine reports that she uses her insulin “like I’m supposed to” and attributes her weight loss to “being busy.” Her parents tell Dr. Green that Francine has been avoiding eating with them at dinnertime, asking to eat her meals alone in her room, where she is “always on the computer or her phone.” Since her diagnosis, they have helped to manage her insulin, but she has been refusing their involvement recently. They express concern about her weight loss and worry she may have an eating disorder. A rhythmic gymnast from age 9 to 13, Francine had always been “petite”, but began gaining weight around the time she began taking insulin. Her parents report that for the past 3 years, she has occasionally spoken about feeling “fat”, and that beginning a year ago, she has been frequently crying when getting ready for school (shouting sometimes at her mother, “my clothes don’t fit!”), and becoming more argumentative when shopping for new clothes. Her mother reports that she once walked into Francine’s room and saw on the computer screen an image of an emaciated-appearing teenage girl looking at herself in the mirror, but Francine quickly closed the image and refused to explain what she was viewing. During the session, Dr. Green says to Francine that sometimes teens may skip insulin doses in order to lose weight—asking, “have you ever tried that?” Francine’s response is an angry, “that sounds crazy.”

Preferred diagnosis: other specified feeding or eating disorder (normal weight; insulin overuse for weight loss).

Francine exemplifies the kind of patient that can be commonly seen in primary care and specialty medical practice, as well as general psychiatric practice—a patient who seems to have substantial concerns about body image and weight, and who is most likely manipulating her eating and calorie balance (in her case, through insulin omission), but who may not cleanly fit into a specific feeding or eating disorder. This presentation is common enough to have been colloquially labeled “diabulimia” .

At the time that Francine’s endocrinologist referred her to see Dr. Green, Francine was not underweight and—at least during this initial evaluation—was denying engaging in excessive means to lose weight; she therefore would not (at least while she still maintains a normal weight) fulfill criteria for anorexia nervosa (AN; see Chap. 1 for more discussion of this diagnosis). She was also denying binge-eating episodes and, as such, was not fitting a diagnosis of bulimia nervosa (BN; see Chap. 7 for more discussion of this diagnosis). On the other hand, her parents were sensing clues that raised their suspicion for an eating disorder, including Francine’s increased preoccupation with her body shape and weight. With further evaluation by Dr. Green over a few sessions, it becomes clear that Francine is taking measures to lose weight, including both calorie restriction and insulin omission, and she is doing this in the setting of body dissatisfaction. Francine has an eating disorder, and—despite its not fitting neatly into one of the major feeding or eating disorder diagnoses—it is important to identify the condition and address it; left untreated, this pattern of problematic eating-related behavior and distorted ideas about body image may progress, resulting in substantial psychiatric and medical morbidity.

Dr. Green assigns the diagnosis of other specified feeding or eating Disorder (normal weight; insulin overuse for weight loss). OSFED [see Text box: OSFED: DSM-5 Diagnostic Criteria], a diagnosis new to the DSM-5 [see Text box: Spotlight on DSM-5: OSFED], should be used when there are relevant symptoms of an eating disorder considered worthy of clinical attention, where the symptoms do not fit into one of the specified diagnoses but the nature of the eating disorder can be described in specific terms. In Francine’s case, she remains within normal weight and is misusing insulin and calorie restriction for weight loss.