Genetic and Environmental Aspects of Eating Disorders

In this chapter, we review the evidence for the relevance of family factors in the aetiology of eating disorder. The focus is on evidence compiled in recent systematic reviews and/or from well-powered community and clinically based studies. Both genetic and environmental factors within families impact on the risk of developing an eating disorder. Large international studies have led to greater understanding of the genetic underpinnings of anorexia nervosa. Similar studies for the binge spectrum disorders are now in progress. Eating disorders (particularly those within the binge spectrum disorders) are associated with a genetic profile shared with many other psychiatric disorders. However, a unique aspect of the genetic risk for eating disorders is the association with the anthropometric and metabolic genetic profile. Interestingly, this somatic profile shows contrasts across the range of eating disorders. Environmental factors within the family context also moderate the risk of developing an eating disorder. These range from generically stressful events and specific stresses related to weight stigma or “fat talk” to influences within the food environment. Critical developmental stages such as puberty or transitions increase the risk of an eating disorder, possibly through interactions with the genetic and family environment. Prevention programs which target some of the specific environmental risk factors have been developed and may be of value for those with a high familial risk.