An examination of the food addiction construct in obese patients with binge eating disorder

Excessive food consumption and its relation to obesity and binge eating represents a pressing clinical and public health concern1,2. A growing body of literature has found a number of similarities linking excess food consumption with addiction. First, animal models have found that rats given access to sugar, fat, or processed foods exhibit altered reward-related neural mechanisms that are implicated in addictive behaviors3,4. Further, these rats exhibit behavioral hallmarks of addiction, such as tolerance, withdrawal, binge consumption, and continued use despite the receipt of negative consequences (i.e., electric shocks)3,4. In humans, obesity and substance dependence have both been linked to similar neural markers, such as reduced DRD2 receptors5,6 and food and drug cravings are also associated with similar patterns of dopamine-related neural activation7,8,9. Finally, many of the behavioral indicators of addiction also appear to be common in problematic eating behavior, such as loss of control, continued use despite negative consequences, and an inability to cut down problematic use10. The concept of “food addiction” represents a controversial issue, for various reasons including the simple fact that drugs – unlike food – are not required for survival. This controversy is exemplified by the lack of an accepted definition of food addiction, despite accepted working definitions of eating disorders in both the clinical and research literature. Partly in response to these issues, Gearhardt and colleagues11 developed the Yale Food Addiction Scale (YFAS) as an attempt to operationalize the concept of “food addiction.” The YFAS translates the substance dependence diagnostic criteria outlined in the Diagnostic and Statistical Manual IV-TR12 to apply to eating behavior. The YFAS provides two scoring options, one option that measures food addiction “symptoms” and another option that provides a food addiction “diagnosis” based upon the substance dependence diagnosis in the DSM-IV-TR12. In the initial validation, the YFAS exhibited adequate internal reliability, as well as convergent and incremental validity11. Although encouraging, the initial validation of the YFAS utilized a non-clinical undergraduate sample and further psychometric examination using clinical samples is needed. The examination of the YFAS in a clinical sample such as binge eating disorder (BED) may be useful in answering questions of validity. BED is characterized by recurrent binge eating (i.e., consumption of unusually large amounts of food in discrete times while experiencing a subjective sense of loss of control) without compensatory weight control behaviors, such as purging. Features associated with BED, such as periodic loss of control over consumption of food; eating when depressed or bored; feeling disgusted, depressed, or guilty after binge eating; eating until physically uncomfortable due to the amount of food just consumed, appear similar to features associated with substance dependence13. In a non-clinical sample, the YFAS predicted binge eating scores above and beyond existing measures of eating pathology11. Thus, the examination of the YFAS in patients with BED is an important step in evaluating the validity of the food addiction concept in a clinical sample. In the present study, we examined the nature of “food addiction” as assessed by the YFAS in obese patients seeking treatment for BED. This is the first psychometric evaluation of the YFAS in a clinical sample of obese patients with disordered eating and is an examination of the association between the food addiction concept and specific eating pathology and associated psychopathology. We considered pathological signs and symptoms, such as negative affect, difficulties in emotional regulation and self-esteem, that have been implicated clinically and empirically in substance use problems as well as eating/weight problems. Additionally, we examined whether the YFAS accounted for variance in binge eating frequency above and beyond other measures of eating pathology.