In a study involving 133 overweight women, those with a genetic predisposition to benefit from a low-carbohydrate diet lost 2 1/2 times as much weight as those on the same diet without the predisposition. Similarly, women with a genetic makeup that favored a low-fat diet lost substantially more weight than women who curbed fat calories without low-fat genes. The women were followed for a year. Read more here Genetics Test Helps Predict Weight-Loss Success, Study Says – WSJ.com