A study examines how those who use driven exercise to lose weight might fit into the ED spectrum.
The DSM-5 category of “Other Specified Feeding and Eating Disorders” includes disordered eating behaviors that are still being defined.  One of these, purging disorder (PD), is common and causes high levels of impairment and distress.
Janet Lydecker, Morgan Shea, and Carlos M. Grilo recently reported that individuals who regularly engage in compulsive and driven exercise to control their weight exhibit characteristics similar to people who use traditional purging behavior (laxative abuse or vomiting) to control their weight (Int J Eat Disord. 2017; doi:10.1002/eat.2281).
To investigate the use of driven exercise and weight control, the trio of researchers recruited 2,026 participants using Mechanical Turk, an online tool. The participants self-reported their current weight and height, which was used to calculate body mass index.  Participants also filled out a series of questionnaires, including a shortened version of the Eating Disorder Examination, the Godin Leisure Time Exercise Questionnaire, which records the frequency of physical activity across levels of intensity during a typical week, and the Patient Health Questionnaire-2, which assesses recent mood state. The participants were also categorized into several groups, those with regular compensatory driven exercise (297),  those who regularly used vomiting/laxatives (59), individuals with broadly defined AN (20), and those with no eating disordered behaviors (1, 658).
Higher levels of depression were identified among three groups
The authors reported that individuals who habitually used compensatory exercise, regular compensatory vomiting or laxative use, and those with diagnoses of AN had higher degrees of eating disorder psychopathology and physical activity than did those with no eating disorders. However, the groups did not significantly differ from one another on most domains. Those who used compensatory vomiting/laxatives and those with AN had higher levels of depression than did those with regularly compensatory driven exercise.
The authors’ study provides new information about driven exercise as a form of PD in the psychopathology of persons who regularly binge-purge and use other compensatory behaviors but do not binge-eat. In general, there was little or no evidence for the exercise group being less severely ill than the traditional PD or AN groups. This “makes it [driven exercise] an important behavioral feature of EDs to assess epidemiologically as well as in clinical studies with individual patients,” the authors remarked.