Genes tied to body mass set point

Genes may help determine why some mice (and perhaps people) become obese when eating a sugar- and fat-laden diet, while others can, to a certain extent, fend off the extra pounds. Working with about 100 types of mice, Aldons Lusis of UCLA and colleagues found that most strains gained weight when fed a high-fat, high-sucrose diet, but stopped gaining weight after a few weeks on the high-calorie diet.