Disordered eating in diet-treated inborn errors of metabolism: screening and behavioral insights

Lifelong restrictive diets are a mainstay of management for many inborn errors of metabolism (IEMs). The experience of metabolic care providers suggests higher prevalence of disordered eating behaviors in this population; however, this has not been well characterized. In this study, we applied screening tools adapted to our population to identify eating disorders and characterize associated symptomatology. All participants were given 2 assessment tools: the SCOFF questionnaire, a 5-question screen for a possible eating disorder, and a modified Eating Pathology Symptoms Inventory (EPSI), a 45-item Likert-scaled questionnaire characterizing eating disorder pathology. Patients aged 16 years and older on prescription diets at the Program for Inherited Metabolic Diseases at the Icahn School of Medicine at Mount Sinai were recruited. Participant demographics were collected through medical record review.

Fifty-two subjects were enrolled, and 51 completed both surveys. 27 subjects identified as female (52%), 23 as male (44%), and two as genderqueer (4%). Ages ranged from 16 to 50 years old. The most common diagnosis was phenylketonuria (n = 34, 65%), followed by glycogen storage disease type 1a (n = 8, 15%). Most patients were on a low-protein diet (n = 41, 79%), 17% (n = 9) were on a low-carbohydrate diet, and 6% (n = 3) were on a low-fat diet. The SCOFF screen positive rate was 34.6%, 95% CI [22.0% - 49.1%], which is significantly greater than population norms of 10.1% (p < 0.001). EPSI results revealed that our participants were significantly more likely to demonstrate binge eating, restrictive behaviors, excessive exercise, and negative attitudes towards obesity when compared to population norms.

This study demonstrates a significantly increased screen positive rate of likely eating disorders among patients with IEM, about three times that of the general population. Metabolic providers should be aware of this potential risk to their patients, as eating disorders can impact metabolic control and adherence to diet, while also causing significant psychological distress to patients with these rare disorders. These results demonstrate that heightened awareness of potential eating disorders in patients with IEMs is warranted, and the development of validated screening tools may be impactful to their care and management.