People who carry a variant in the so-called obesity gene, FTO, react just as well to diet and exercise as those without it, a research paper said Wednesday. “Individuals carrying the (variant) respond equally well to dietary, physical activity, or drug based weight loss interventions,” wrote the authors of the review of eight studies involving some 10,000 people. Scientists have previously shown an association between a variant of the FTO gene and surplus body fat, but little is understood about how the link works.