Everyone who has struggled with losing weight knows that sometimes the spirit is willing but the genes are weak. Still, there's hope: a study of the Amish found that even people with a genetic predisposition to gain weight can control their body size. Some subjects carried a fattening variant of the FTO gene associated with obesity. The Amish FTO carriers were indeed an average of 7 lb. (3.2 kg) heavier than people without the gene. Even within this subgroup, however, some were able to avoid getting fat — thanks to simple exercise. The catch was that it took a lot more physical activity for people with the gene variant to stay slim than for those without it. Still, in this one case, we can apparently nurture nature.