An experiment assessing effects of personalized feedback about genetic susceptibility to obesity on attitudes towards diet and exercise

As increasing attention is paid to possible genetic influences on susceptibility to obesity, recent studies have examined how genetic attributions can impact laypeople's weight-related attitudes and eating behavior. Little consideration, however, has been devoted to understanding the potential effects of learning that one does not have a genetic predisposition to obesity. The present study investigated the possibility that such feedback might bring about negative consequences by making people feel invulnerable to weight gain, which is termed a genetic invincibility effect. After conducting a saliva test disguised as genetic screening, participants were randomly assigned to be told that there was either a very high or very low chance that they carried genes known to increase one's risk of developing obesity. Participants who were told that they were not genetically predisposed to obesity judged the efficacy of healthy diet and exercise habits to be significantly lower than did those who were told that they were genetically predisposed and those who did not receive any genetic feedback. When prompted to select a meal from a menu of options, participants who were told that they were not genetically predisposed to obesity were also more likely than others to select unhealthy foods. These findings demonstrate the existence of a genetic invincibility effect, suggesting that personalized feedback indicating the absence of a genetic liability could have negative psychological consequences with substantial health-related implications.