Author	S.F. Meisel
Author	J. Wardle
Abstract	The value of genetic test feedback for common conditions is widely debated. This is principally because of the lack of impact on behaviour change of feedback for genes with small effect sizes, but also because of concern about the risks of fatalistic responses to positive test results or false reassurance from negative results. This thesis describes research using feedback for one gene, FTO, implicated in the development of obesity, as a model to investigate motivational and emotional reactions to testing for genetic susceptibility. It comprises a series of six studies examining the benefits and harms associated with genetic test feedback. They incorporated a mixture of qualitative and quantitative methodologies, used hypothetical and real genetic feedback, and tested predominantly normal-weight students and overweight/and obese individuals from a web panel. Fatalism or false reassurance in response to FTO genetic test feedback was not observed in any of the studies. Genetic test feedback was consistently perceived as motivating, and negative emotional effects of a higher-risk FTO gene result were minimal. Overweight and obese individuals found the test result helpful for alleviating guilt and stigma; although in response to an unexpected lower-risk genetic test result, some were disappointed. University is notoriously a life stage with risk of weight gain but not all students gain weight. One study examined associations between genetic risk status and weight gain, and found that students with at least one higher-risk allele were more likely to gain weight. The final study was a randomised controlled trial examining the effect of giving FTO feedback alongside simple weight control advice to first year students. Short-term (one month) results showed that weight control intentions were significantly higher in those randomised to receive FTO feedback and weight control advice than weight control advice alone, but there was no effect on weight or reported behaviour change. Although the studies in this thesis had many limitations, the findings indicate that people are unlikely to misinterpret or overstate the impact of genetic test results, at least in the context of a single gene implicated in a multifactorial condition. However, effects on behaviour remained elusive. This indicates the need for future research to learn how to harness the potential of genetic information to promote personalised prevention.