Toward a Better Definition of Food Addiction

Is food addiction, or FA, often formally defined as a substance-use disorder, actually connected with an eating disorder, especially binge eating disorder, or BED? Dr. Ester di Giacomo of the University of Milan, Italy, and her colleagues recently sought to answer this question with a review and meta-analysis. They explored whether food addiction occurs with a specific eating disorder or as a separate entity, or is comorbid with eating disorders or other conditions such as obesity, and if FA exists in the general population (Eat Weight Disord.2022. 27:1963).

“Food addiction” is a term coined to demonstrate behavior that resembles that of substance-use disorder. The definition of substance-use disorder includes a strong urge to consume, made worse by abstinence, followed by failure to limit consumption (in this case, of food) despite awareness of the side effects. A person with FA eats despite feeling full, has cravings without hunger, and has feelings of guilt or shame soon after eating excessive amounts of food. As the authors point out, many neurobiochemical and neurogenetic studies have shown that typical mechanisms of FA are crucial in problematic nutrition. Genetic similarities between overeating and substance addiction have been identified as variants in genes encoding the dopamine D2 receptor.

Food addiction is not yet categorized in the Diagnostic and Statistical Manual of Mental Disorders, or DSM, but shares many overlapping criteria of DSM-5 Substance Use Disorder, including a substance taken in larger quantities and for a longer period than expected, a persistent desire or repeated failed attempts to stop over-consuming the substance, a large amount of time used to obtain, use, or dispose of a substance, and withdrawal symptoms, among others.

A scale to categorize FA

The Yale Food Addiction Scale (YFAS) was developed in an attempt to categorize the concept of FA. This 25-item self-report questionnaire adapts the diagnostic criteria of substance dependence outlined by the DSM-IV-TR to eating behavior or abuse of specific foods, and is the only validated tool currently available for assessing “food addiction.” The authors note that more than 11% of the general population may show symptoms of FA, while from 25% to 42% of obese patients meet the YFAS criteria.

The authors identified six studies involving 2476 subjects (539 affected by BED, 178 by BN, 18 by an eating disorder not otherwise specified (EDNOS), 65 by restrictive-type AN, 33 by purging-type AN, 442 with obesity, and 1146 from the general population, who had no eating disorders).

A connection with BED

The authors found that patients with BED had an increased prevalence of meeting FA criteria compared to patients with other eating disorders. BED, BN, and FA have overlapping symptoms. “It is crucial to underline that FA is also detected in persons with no eating disorders or obesity, but also in persons from the general population who have no psychiatric issues,” say the authors. The authors interpret these findings to show that FA is a separate and distinct diagnostic entity.

The finding of FA symptoms independent from having other ED symptoms is an interesting and important point. However, in considering a possible diagnostic entity one would also be interested in establishing predictive validity: Does having an FA diagnosis inform outcome or treatment response? This will be critical in supporting FA as a separate diagnosis.