Background and objectives: Although more and more genetic information is available, it is unclear whether this information is helpful for patients. Therefore, we assessed the positive and negative effects of informing obese people about the genetic etiology of being overweight.
Design, participants: Two hundred ninety-four obese people were randomized to 2 interventions (a 1-session consultation for obese people on how to manage obesity either including genetic information or not); their results were compared to a control group (116). Subjects were assessed before and after consultation and 6 months later.
Measurements: Weight, scales on feeling guilty for being overweight, self-control, negative mood (primary endpoint), body acceptance, restraint eating.
Results: Both types of consultations were considered helpful by the participants, and had comparable effects on body weight. The consultation with genetic information was rated superior in terms of leading to new insights (advantage for consultation with genetic information, even 6 months later; p = 0.046). No negative effects (e.g., loss of self-efficacy/self-control, increase of body weight; all p > 0.20 for interaction consultation x time) were observed for informing obese people about the genetic etiology of being overweight. The consultation resulted in long-term improvement of negative mood if it included genetic information in the case of participants with a family history of obesity and if it included no genetic information in the case of obese people without a family history of obesity (p = 0.03 for interaction of group, intervention, and time).
Conclusions: Consultations in obesity can be helpful in general. These consultations should include genetic information if people have a family history of obesity.