Research

Physiogenomic comparison of human fat loss in response to diets restrictive of carbohydrate or fat

Richard L Seip^1,2 , Jeff S Volek³ , Andreas Windemuth¹ , Mohan Kocherla¹ , Maria Luz Fernandez⁴ , William J Kraemer³ and Gualberto Ruaño¹

¹  Genomas, Inc., 67 Jefferson St, Hartford, Connecticut, USA

²  Department of Cardiology, Hartford Hospital, Hartford, Connecticut, USA

³  Department of Kinesiology, University of Connecticut, Storrs, Connecticut, USA

⁴  Department of Nutritional Sciences, University of Connecticut, Storrs, Connecticut, USA

author email corresponding author email

Nutrition & Metabolism 2008, 5:4doi:10.1186/1743-7075-5-4

Published:	6 February 2008

Abstract

Background

Genetic factors that predict responses to diet may ultimately be used to individualize dietary recommendations. We used physiogenomics to explore associations among polymorphisms in candidate genes and changes in relative body fat (Δ%BF) to low fat and low carbohydrate diets.

Methods

We assessed Δ%BF using dual energy X-ray absorptiometry (DXA) in 93 healthy adults who consumed a low carbohydrate diet (carbohydrate ~12% total energy) (LC diet) and in 70, a low fat diet (fat ~25% total energy) (LF diet). Fifty-three single nucleotide polymorphisms (SNPs) selected from 28 candidate genes involved in food intake, energy homeostasis, and adipocyte regulation were ranked according to probability of association with the change in %BF using multiple linear regression.

Results

Dieting reduced %BF by 3.0 ± 2.6% (absolute units) for LC and 1.9 ± 1.6% for LF (p < 0.01). SNPs in nine genes were significantly associated with Δ%BF, with four significant after correction for multiple statistical testing: rs322695 near the retinoic acid receptor beta (RARB) (p < 0.005), rs2838549 in the hepatic phosphofructokinase (PFKL), and rs3100722 in the histamine N-methyl transferase (HNMT) genes (both p < 0.041) due to LF; and the rs5950584 SNP in the angiotensin receptor Type II (AGTR2) gene due to LC (p < 0.021).

Conclusion

Fat loss under LC and LF diet regimes appears to have distinct mechanisms, with PFKL and HNMT and RARB involved in fat restriction; and AGTR2 involved in carbohydrate restriction. These discoveries could provide clues to important physiologic mechanisms underlying the Δ%BF to low carbohydrate and low fat diets.