To understand the similarities and differences between the genetic patterns of anorexia nervosa, bulimia nervosa and binge-eating disorder, the research team analysed the genomes of more than 20,000 people. These were taken from two large population-based studies conducted in the UK: the UK Biobank and the Avon Longitudinal Study of Parents and Children.
“The similarities lie in the association with psychiatric risks: anorexia nervosa, bulimia nervosa and binge-eating disorder share genetic risk with certain psychiatric disorders, in particular for schizophrenia and depression, thus confirming the strong psychiatric component of these diseases,” [researcher Nadia] Micali said. “However, the big difference concerns the associated genetics of body weight regulation, which are opposite between anorexia on the one hand, and bulimia nervosa and binge-eating disorder on the other, the latter being linked to a high genetic risk of obesity and high BMI.”
A genetic predisposition to a heavy weight versus a light weight may constitute a determining factor that pushes individuals with similar psychiatric genetic risk to different eating disorders. As noted by Prof Micali, “The metabolic and physical component would therefore direct the individual either towards anorexia nervosa or towards bulimia nervosa or binge-eating disorder.”