Background: Differences in weight loss between isocaloric high- carbohydrate and high-fat diets are generally small; however, weight loss responses vary within diet groups. Genotype patterns may modify the effects of diets, but findings are equivocal. We investigated whether weight loss on a diet concordant with one’s presumed geno- type (fat-responsive vs. carbohydrate-responsive genotype) differs from weight loss on a diet discordant with one’s genotype. Methods: The Personalized Nutrition Study (POINTS) was a 12-week weight loss trial that enrolled 145 participants with overweight or obesity into one of four groups: (1) presumed fat-responsive genotype receiving a high-fat diet, (2) fat-responsive genotype receiving a high- carbohydrate diet, (3) carbohydrate-responsive genotype receiving a high-fat diet, and (4) carbohydrate-responsive genotype receiving a high-carbohydrate diet. Carbohydrate- and fat-responders were iden- tified a priori based on their combined genotypes at 10 genetic vari- ants. Dietitians delivered the weight loss intervention via 12 weekly diet-specific small group sessions. The primary outcome was 12-week weight change (kg and %). Results: In total, 122 participants (54.4 [SD=13.2] years, BMI 34.9 [SD=5.1] kg/m2, 84% women, 68% White) were included in the analyses. Weight change at 12 weeks was "5.3 kg (95% CI: "6.4, "4.2) in the genotype-concordant diet groups (groups 1 and 4 com- bined) compared to "4.7 kg (95% CI: "5.8, "3.6) in the genotype- discordant diet groups (groups 2 and 3), with no significant differ- ence between the groups (p=0.501). Results were similar for per- cent weight loss. When analyzing fat responders (n=85) and arbohydrate responders (n=37) separately, we similarly found no difference in weight change (kg) between those with a genotype- concordant diet and those with a genotype-discordant diet (p=0.779 and p=0.487, respectively). Conclusions: Our results suggest that weight loss on a high-fat diet compared to a high-carbohydrate diet does not differ by genotype.     «

Background: Differences in weight loss between isocaloric high- carbohydrate and high-fat diets are generally small; however, weight loss responses vary within diet groups. Genotype patterns may modify the effects of diets, but findings are equivocal. We investigated whether weight loss on a diet concordant with one’s presumed geno- type (fat-responsive vs. carbohydrate-responsive genotype) differs from weight loss on a diet discordant with one’s genotype. Methods: The Personalized Nutrition S...     »