Abstract MP25: Dietary Fat Intake, Mc4r Genotype and 2-Year Changes in Body Composition: The Pounds Lost Trial
Background: Melanocortin receptor 4 (MC4R) is a key protein regulating dietary intake and adiposity in humans. MC4R gene variants have been associated with fat intake, fat mass, weight change, and risk of obesity. Observational studies have suggested that dietary fat may modify these effects; however, this has yet to be verified in long-term randomized clinical trials.
Objective: To examine the interaction between an “obesity-predisposing” MC4R variant and fat intake on long-term changes in body composition in the context of a randomized controlled trial.
Design and Methods: We genotyped MC4R rs17782313 and assessed body composition in 373 overweight adults in the 2-year Preventing Overweight Using Novel Dietary Strategies (Pounds Lost) trial.
Results: We found significant interactions between the MC4R rs17782313 and dietary fat intake on changes in lean mass and total mass at 6 months (p for interaction=0.019 and 0.012, respectively) after adjusting for age, sex, ethnicity, baseline BMI, 6 months weight loss, and baseline perspective outcomes. The C allele was significantly associated with a greater increase in lean mass and total mass in the low-fat diet group (P=0.008 and 0.005, respectively), but not associated with these measures in the high-fat diet group at 6 months (P>0.05, respectively) (Figure 1). We didn’t observe significant genotype-diet interaction on changes in body compositions at 24 months, probably due to regain of body weight after 6 months.
Conclusions: Our data suggest that individuals with the MC4R rs17782313 C allele might experience greater increases in lean mass and total mass when consuming a lower fat weight-loss diet.
Keywords: MC4R genotype, body composition, gene-diet interaction, weight-loss trial
Author Disclosures: T. Huang: None. Y. Shen: None. Y. Zheng: None. S. Smith: None. G. Bray: None. F. Sacks: None. L. Qi: None.
- © 2015 by American Heart Association, Inc.