The July issue of Pediatrics reports convincing evidence (from an investigation of twins growing up in different environments) that up to 80% of the variation in body fat between children is genetic and not due to diet or exercise. Obese kids often don't eat more or exercise less than their thin peers. It's not their fault! Still, to trim down the best bets are less TV and more time outdoors (getting kids moving in active play), and less junk foods and more whole foods in the diet. They'll need more effort to achieve the same results. Sometimes life just isn't fair!