Finding: Genetic Risk for Obesity Influences Intention to Lose Weight

November 2016

In the United States, more than one third of all adults are obese. Obesity is defined as the excessive storage of body fat that occurs when more calories are consumed than are burned through exercise and normal daily activities. As much as 86% of the risk for becoming obese can be attributed to genetic risk factors, while the remaining 14% of the risk is believed to correspond to lifestyle and environmental risk factors. Being obese increases your risk for other serious health problems, such as heart disease, high blood pressure and diabetes. Fortunately, even modest weight loss can prevent the development of health problems associated with obesity.

To determine the impact of providing personalized obesity risk information on weight and intention to lose weight, the BU-CPMC Study Team recruited 696 CPMC participants and randomly assigned each of them to receive one of four different versions of the CPMC Obesity Risk Report: 1) educational information only (control group), 2) genetic risk only, 3) lifestyle risk only, or 4) genetic and lifestyle risks. Participants completed survey questions about their current weight and intentions to lose weight before viewing their results and 3 months after viewing their results.

Participants who received only genetic risk information for obesity reported the greatest intentions to lose weight. Those who received both lifestyle and genetic risk for obesity were also more likely to report intentions to lose weight. Interestingly, the intention to lose weight was higher among participants of normal weight (BMI 18.5-24.9) than among participants who were overweight (BMI 25-29.9) or obese (BMI ≥ 30). This finding suggests that genetic risk information may be more motivating for those who are not yet overweight and may be viewed as a reason to take action to reduce the likelihood of future weight gain. No differences between baseline and follow-up in self-reported weight were found in any of the four groups.

Previous studies exploring the impact of genetic risk information on motivation to lose weight have had conflicting results. Some individuals have found genetic risk information for obesity to be motivating, while others have had the opposite response, interpreting genetic risk for obesity as insurmountable. Our study results indicated that participants who received genetic risk information (either alone or with lifestyle risk) reported greater intentions to lose weight than those who received no risk information or lifestyle risk information only. More research is needed to determine how genetic risk information is motivating and to better understand which individuals may be motivated by genetic risk.

This paper will be published in an upcoming issue of the journal Obesity.