Gene variation in FTO linked to higher risk of binge-eating in teenagers, new study finds
Researchers from the University of Queensland’s UQ Diamantina Institute, working with a team at the University College London Institute of Child Health, report that a common genetic variation is associated with an increased likelihood of binge-eating among adolescents. The study analysed data from roughly 6,000 young people aged 14 and 16 and found that some obesity-related genetic markers also predict binge-eating behaviour in adolescence.
Professor David Evans, a lead investigator on the study, says the discovery helps clarify why some young people are more prone to episodes of uncontrolled eating. Identifying genetic contributors could improve understanding of the early signs and mechanisms that lead to binge-eating and, in some cases, to subsequent overweight and obesity.
“Recognising genetic risk factors may in the future help health professionals identify teenagers who are at greater risk before they develop weight-related health problems,” Professor Evans said. He emphasised that binge-eating is a complex behaviour shaped by many genetic and environmental influences and that this finding represents an early step toward understanding those interactions.
In the study, one variation in the FTO gene stood out. Adolescents carrying this specific FTO polymorphism showed a 20 to 30 percent greater likelihood of reporting binge-eating behaviours than those without it. The effect was especially pronounced in girls, who were roughly 30 percent more likely to binge-eat when they carried the variation.
Binge-eating in this context was defined as episodes of excessive food consumption accompanied by a perceived loss of control. Previous work has established that roughly 10 percent of adolescents and adults experience binge-eating. While environmental factors such as family dynamics, dieting behaviours and social influences contribute to risk, this study highlights a measurable genetic component linked to appetite regulation and body mass index (BMI).
The investigators tested 32 single-nucleotide polymorphisms (SNPs) that have been robustly associated with BMI. They examined whether those BMI-related variants, individually and combined as a weighted allelic score, were associated with self-reported binge-eating at ages 14 and 16 in the Avon Longitudinal Study of Parents and Children cohort.
Results from crude analyses identified a clear association between binge-eating and the SNP rs1558902 in the FTO gene. That association remained significant after adjustment for BMI, age and sex, supporting the idea that the FTO variant relates to binge-eating behaviour independent of body mass. When all 32 BMI-related SNPs were combined into a weighted score, that aggregate measure was also associated with binge-eating; however, removing the FTO variant weakened the association, implicating FTO as a primary driver of the combined effect.
Although replication in other cohorts is needed, the authors note that the findings are biologically plausible. Prior research links FTO to appetite regulation and food intake, and the current results are consistent with a model in which FTO variants contribute to both increased BMI and a greater tendency to binge-eat. Understanding the mechanisms — for example, how FTO influences hunger signalling, reward response to food, or impulse control — will require further study.
Funding: This work was supported by the Medical Research Council (MC_UU_12013/4). DME is funded by an Australian Research Council Future Fellowship (FT130101709). The UK Medical Research Council and the Wellcome Trust (grant refs: 092731 and 102215/2/13/2) and the University of Bristol provide core support for the ALSPAC study. 23andMe supported generation of ALSPAC genome-wide association data. Additional funding included a National Institute of Health Research clinician scientist award to Dr N. Micali (DHCS/08/08/012). The views expressed are those of the authors and do not necessarily represent the NHS, the National Institute for Health Research, or the Department of Health. Part of this work was conducted in the Medical Research Council Integrative Epidemiology Unit (MC_UU_12013/4).
Source: David Evans – University of Queensland
Image credit: NeuroscienceNews.com
Original research: “Are obesity risk genes associated with binge eating in adolescence?” by Nadia Micali, Alison E. Field, Janet L. Treasure and David M. Evans, published in Obesity. Published online July 20, 2015. DOI: 10.1002/oby.21147
Abstract
Are obesity risk genes associated with binge eating in adolescence?
Objective
The study tested whether cognitive and behavioural features of binge-eating are related to genetic polymorphisms previously linked to BMI and obesity risk, with a focus on a polymorphism in the FTO gene. The authors hypothesised that higher BMI and binge-eating might share a common genetic basis.
Methods
Binge-eating was assessed in adolescents from the Avon Longitudinal Study of Parents and Children at age 14 (n = 5,958) and age 16 (n = 4,948). Researchers evaluated associations between 32 BMI-related SNPs and binge-eating using regression models adjusted for BMI, age and gender where appropriate.
Results
Initial analyses showed an association between binge-eating and rs1558902 (FTO). This relationship persisted after adjustment for BMI (odds ratio = 1.20, P = 8 × 10−3). A weighted allelic score combining all 32 BMI-associated SNPs was also associated with binge-eating (P = 8 × 10−4); the association diminished (P = 0.08) when the FTO variant was removed from the score.
Conclusions
Genes related to BMI appear to be associated with adolescent binge-eating, particularly an FTO polymorphism. While additional studies are required to replicate these results and to elucidate mechanisms, the findings align with existing evidence that FTO can affect appetite and food intake. Future research should investigate how FTO-related mechanisms link binge-eating behaviour with obesity risk.