Differences in Weight Loss Between Persons on Standard Balanced vs Nutrigenetic Diets in a Randomized Controlled Trial

Background & Aims Many companies provide genetic tests for obesity-related polymorphisms (nutrigenetics) and make dietary recommendations for weight loss that are based on the results. We performed a randomized controlled trial to determine whether more participants who followed a nutrigenetic-guided diet lost ≥5% of their body weight than participants on a standard balanced diet for 8 and 24 weeks. Methods We performed a prospective study of 51 obese or overweight U.S. veterans on an established weight management program at the Veterans Administration San Diego Healthcare System (the MOVE! program). Participants were randomly assigned to groups placed on a nutrigenetic-guided diet (balanced, low-carbohydrate, low-fat, or Mediterranean; n = 30) or a standard balanced diet (n = 21). Nutrigenetic diets were selected on the basis of results from the Pathway FIT test. Results There was no significant difference in the percentage of participants on the balanced diet vs the nutrigenetic-guided diet who lost 5% of their body weight at 8 weeks (35.0% ± 20.9% vs 26.9% ± 17.1%, respectively; P  = .28) or at 24 weeks. Both groups had difficulty adhering to the diets. However, adherence to the nutrigenetic-guided diet correlated with weight loss ( r  = 0.74; P  = 4.0 × 10 −5 ), but not adherence to standard therapy ( r  = 0.34; P  = .23). Participants who had low-risk polymorphisms for obesity lost more weight than all other participants at 8 weeks (5.0% vs 2.9%, respectively; P  = .02) and had significantly greater reductions in body mass index (6.4% vs 3.6%, respectively; P  = .03) and waist circumference (6.5% vs 2.6%, respectively; P  = .02) at 24 weeks. Conclusions In a prospective study, a nutrigenetic-based diet did not increase weight loss compared with a standard balanced diet. However, genetic features can identify individuals most likely to benefit from a balanced diet weight loss strategy; these findings require further investigation. ClinicalTrials.gov number: NCT01859403.