Is obesity in our genes? Dr. Elizabeth Speliotes, M.D., Ph.D., M.P.H., explains the role genes play in body size and shape. By analyzing genetic samples of 300,000 individuals across the globe, researchers have found more than 100 locations across the genome linked with obesity traits. These genetic clues may one day help doctors tailor the advice they give to patients about obesity complications. The study was published in the 12 Feb. issue of Nature.