Anorexia nervosa and bulimia often begin during puberty or shortly afterwards. Significant increases in disordered eating have been found during puberty with girls becoming more preoccupied about their weight, more dissatisfied with their bodies and more likely to binge eat. One theory is that the physical changes which occur during puberty, specifically an increase in body fat, lead to girls becoming more dissatisfied with their bodies. Recent studies have also shown that there is a genetic influence on this process and a study of 510 twins in Minnesota has found that the further into puberty the girls were the more influence genetic factors had on their eating behaviour. The researchers concluded that although social and psychological factors remained important the genetic element to eating disorders should also be taken into account.
Klump, Kelly L. ... [et al] - Puberty moderates genetic influences on disordered eating Psychological Medicine May 2007, 37(5), 627-634