Impact of obesity risk genetic test feedback on intentions to be physically active: A hypothetical scenario study

Background: Obesity is a major public health concern. Although genome wide association studies have identified common variants in genes (e.g. FTO) associated with susceptibility to obesity, recent evidence suggests that physical activity can attenuate this genetic susceptibility. It is therefore important to determine whether individuals who are informed that they have a genetic susceptibility to obesity increase their intention to be physically active.

Methods: In this experimental hypothetical scenario study, 191 participants were asked to imagine they had received a genetic test result indicating high eating-based (n=37) or high metabolism-based (n=41) risk of obesity, an enzyme test result indicating high eating-based (n=35) or high metabolism-based (n=41) risk of obesity, or no risk information (n=37). Outcomes included intention to exercise, exercise self-efficacy (confidence in ability to exercise) and response efficacy (confidence that exercise will reduce obesity risk).

Results: Participant mean age was 29.2 (SD 11.2) yrs, range 16-71 years; 70% were female. Based on self-reported height and weight, 9% were underweight, 86% healthy/normal weight, 15% overweight, 3% obese. Intention to exercise was higher in the combined high risk groups than the group receiving no risk information (p=0.008); there was no difference between genetic and enzyme groups. There were no between-group differences in exercise self-efficacy or response efficacy.

Conclusions: Disclosure of personalized genetic information indicating increased risk of obesity may motivate individuals to pursue a more active lifestyle. The effects of results indicating decreased risk, and whether these associations are also found in studies using real genetic information, remain to be determined.