Skinny Genes

Genetic factors may influence ideals about thinness that can lead to anorexia

(RxWiki News) The media has been taking all the blame for the existence of anorexia, but genetics may play a role as well. This discovery could influence anorexia treatment plans in the future.

A recent study compared ideals of thinness between fraternal and identical twins.

Results found that identical twins were 43 percent more likely to share ideals of thinness compared to fraternal twins.

"Talk to a therapist if you have eating concerns."

Jessica Suisman, MA, researcher in the Department of Psychology, and Kelly Klump, PhD, professor of psychology, at Michigan State University, led investigations into genetic influences in eating disorders.

Ms. Suisman said, “We’re all bombarded daily with messages extoling the virtues of being thin, yet…only some women develop what we term thin-ideal internalization.”

“This suggests that genetic factors may make some women more susceptible to this pressure than others.”

For the study, 343 female twins from 12-22 years of age were assessed for their ideals and perceptions concerning thinness.

Each of the participants was given a questionnaire designed to assess how much each of the women wanted to look like thin models and actresses.

Responses to the questionnaire from identical twins, who have 100 percent of the same DNA, were compared to those from fraternal twins, who have 50 percent of the same DNA.

Results of the study showed that identical twins had more similar responses to ideals of thinness than fraternal twins. There was a 43 percent link between genetics and ideals of thinness.

Ms. Suisman said, “We were surprised to find that shared environmental factors, such as exposure to the same media, did not have as big an impact as expected.”

“Instead, non-shared factors that make co-twins different from each other had the greatest impact.”

Dr. Klump said, “This study reveals the need to take a similar approach to the ways in which women buy in to pressure to be thin, by considering how both genetic and environmental factors contribute to the development of thin-ideal internalization.”

What does this mean? Simply, that the media is not 100 percent to blame for the possibility of eating disorders in young women.

Treatment plans for eating disorders may need to take this into account. Further research on the genetic impact of ideation of thinness is necessary to determine its significance. 

This study was published in October in the International Journal of Eating Disorders.

Funding for this study was supported by the National Institute of Mental Health. No conflicts of interest were found.

Review Date: 
October 8, 2012