Obesity susceptibility loci and dietary intake in the Look AHEAD trial

Authors: MCCAFFERY, JEANNE - Warren Alpert Medical School Of Brown University; PAPANDONATOS, GEORGE - Brown University; PETER, INGA - Mount Sinai School Of Medicine; HUGGINS, GORDON - Tufts - New England Medical Center; RAYNOR, HOLLIE - University Of Tennessee; DELAHANTY, LINDA - Harvard Medical School; CHESKIN, LAWRENCE - Johns Hopkins School Of Public Health; BALASUBRAMANYAM, ASHOK - Baylor College Of Medicine; WAGENKNECHT, LYNNE - Wake Forest University; WING, RENA - Warren Alpert Medical School Of Brown University; FOREYT, JOHN - Children'S Nutrition Research Center (CNRC)

Submitted to: The American Journal of Clinical Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/1/2012
Publication Date: 6/1/2012
Citation: Mccaffery, J.M., Papandonatos, G.D., Peter, I., Huggins, G.S., Raynor, H.A., Delahanty, L.M., Cheskin, L.J., Balasubramanyam, A., Wagenknecht, L.E., Wing, R.R., Look AHEAD Research Group. 2012. Obesity susceptibility loci and dietary intake in the Look AHEAD trial. American Journal of Clinical Nutrition. 95(6):1477-1486.

Interpretive Summary: The genetic association and its links to obesity have often been noted, but the mechanisms and processes between the two still remain unclear. This study aimed to determine the link between the genes related to obesity susceptibility and the dietary intake of subjects. Gene regions associated with higher-risks for obesity, as determined from previous gene-wide association studies (GWAS), were compared to the dietary intake, as measured through food-frequency questionnaires, from subjects in the Look AHEAD clinical trial. The study found that certain obesity risk genes were linked significantly predicted various dietary patterns and habits. These included: more eating episodes per day, eating more servings from dairy groups and products, more servings from the meat, eggs, nuts, and beans group, and lower energy use from consumed proteins. These findings suggest that it is possible that there is a genetic component that may affect eating patterns as well as the type of food consumption among overweight, type 2 diabetic patients. Knowing that certain people may be genetically predisposed to overconsumption of food and unhealthy eating habits has many benefits. It offers some insight and knowledge for planning and implementing weight loss and eating strategy programs when dealing with such patients. Further research on the genetic factors and influences of these high risk obesity genes may help medical professionals better tailor treatment for overweight, obese, and type 2 diabetic patients.

Technical Abstract: Genome-wide association studies (GWAS) have identified consistent associations with obesity. However, the mechanisms remain unclear. The objective was to determine the association between obesity susceptibility loci and dietary intake. The association of GWAS-identified obesity risk alleles (FTO, MC4R, SH2B1, BDNF, INSIG2, TNNI3K, NISCH-STAB1, MTIF3, MAP2K5, QPCTL/GIPR, and PPARG) with dietary intake, measured through food-frequency questionnaires, was investigated in 2075 participants from the Look AHEAD (Action for Health in Diabetes) clinical trial. We adjusted for age, sex, population stratification, and study site. Obesity risk alleles at FTO rs1421085 significantly predicted more eating episodes per day (P = 0.001)-an effect that persisted after adjustment for body weight (P = 0.004). Risk variants within BDNF were significantly associated with more servings from the dairy product and the meat, eggs, nuts, and beans food groups (P = 0.004). The risk allele at SH2B1 rs4788099 was significantly associated with more servings of dairy products (P = 0.001), whereas the risk allele at TNNI3K rs1514176 was significantly associated with a lower percentage of energy from protein (P = 0.002). These findings suggest that obesity risk loci may affect the pattern and content of food consumption among overweight or obese individuals with type 2 diabetes.