Higher BMI linked to increased risk of binge-eating disorder in adolescents

By Dr. Priyom Bose, Ph.D.Reviewed by Benedette Cuffari, M.Sc.May 28 2024

A recent study published in the journal Appetite investigates the extent to which body mass index (BMI) is associated with progression from binge-eating behavior to binge-eating disorder (BED).

Study: Association of body mass index with progression from binge-eating behavior into binge-eating disorder among adolescents in the United States: A prospective analysis of pooled data. Image Credit: Doucefleur / Shutterstock.com

What is BED?

BED is defined as recurrent instances of eating large amounts of food in a short period, at least once a week for three months. BED, which also involves loss of eating control (LOC), is the most widely prevalent eating disorder in the United States. Significant social and economic costs are associated with BED, in addition to its adverse effects on an individual's well-being.

Importantly, an individual can engage in binge eating behaviors, which are relatively less severe than BED. In fact, among adolescents in the U.S., the prevalence of binge-eating behaviors is 2.5%.

Nevertheless, previous research has reported a progression of binge-eating behavior into BED in 10-28% of U.S. adolescent girls. Thus, it is imperative to understand BED risk in early adolescents to prevent or enact early intervention strategies to minimize the adverse effects of BED.

About the study

The present study used data on 9,964 adolescents between nine and 13 years of age at enrollment from the Adolescent Brain Cognitive Development (ABCD) study. Binge-eating behaviors and BED were established through a computerized assessment that the parents of the study participants completed.

There remains a lack of data on the potential relationship between BMI and the progression of binge-eating behavior to BED. To this end, the central hypothesis of the current study was that BMI should be associated with a higher risk of BED, irrespective of individuals' binge-eating behavior.

Among adolescents with binge-eating behavior, the association between BMI and risk of progressing to BED was assessed. In the no binge-eating behavior group, the association between BMI and risk of BED onset was also studied.

Study findings

Higher BMI was associated with a greater likelihood of BED, irrespective of the binge-eating behavior status. This result is consistent with prior prospective and cross-sectional associations between BMI, binge-eating symptoms, and BED in adolescents.

BMI was also found to be a risk factor for BED, including among those already exhibiting binge-eating behaviors. The risk of BED onset was particularly increased among those with BMIs in the 85th percentile or higher.

A theoretical mechanism explaining the observed associations could be the restraint theory, which states that chronic efforts to limit food consumption reduce awareness of internal hunger signals and higher salience of external food signals. The greater influence of external signals and the physiological effects of reduced food consumption can lead to binge eating.

A second theory is the dual-pathway model, which posits that the idealization of being thin can generate pressure to look a certain way and body dissatisfaction. This can negatively affect an individual and dieting, both of which can increase the risk of binge-eating behavior.

The transdiagnostic cognitive behavioral theory states that strict dieting and weight-control behaviors arise from an overemphasis on weight/shape/eating, which could encourage binge eating. Weight-related teasing by others could also increase the risk of different forms of disinhibited eating and binge-eating behavior among youth.

Other relevant theories relate to a higher BMI's potential neurobiological and biological effects, which could lead to binge eating. Prior research has shown that higher BMI is associated with changes in brain regions that control impulse control and executive functions, which could contribute to an increased risk of BED. In this regard, the changes in areas pertaining to reward processing and inhibitory control may lead to LOC.

Increased consumption of ultra-processed food products by adolescents could also adversely affect the gut microbiota, which, in turn, negatively influences the production of signaling molecules and neurotransmitters involved in the gut-brain axis. These types of alterations can negatively impact brain function related to reward processing, appetite control, and mood regulation, all of which may increase the risk of binge-eating behavior.

Conclusions

Higher BMI was associated with a greater likelihood of BED, irrespective of binge-eating behavior status. Some of the implications of these findings include early screening of adolescents with higher BMI, as well as more education and awareness campaigns at family and community levels.

Key strengths of the current study include its large and diverse sample and longitudinal design, which enabled the examination of prospective associations. The main limitation is the parent-completed online assessment, as there could be low concordance between child and parent reports on binge eating.

Another limitation of the current study is due to the use of BMI, which fails to distinguish between fat and muscle mass. Other potential limitations include the possibility of residual confounding effects and the inability to establish causality.