Wait, don't we drink low-fat milk to stay slim? Yet a study led by Mark DeBoer, MD, a pediatric endocrinologist at the University of Virginia, found that children who drank skim or 1 percent milk gained more weight than those who drank 2 percent or whole (full-fat) milk. He points out that the same link—fattier milk, lower body-mass index—has also emerged in large, long-term studies on adults.) DeBoer's theory is that milk fat, compared with other calorie sources, makes us feel fuller, longer—so we consume fewer calories overall. Instead, many of us drink the seemingly virtuous but unfilling low-fat stuff— then stuff ourselves with refined sugars and starches afterward.
The lesson: If you're a milk drinker, try whole or 2 percent in lieu of reduced-fat milk. A large Swedish study found that among normal-weight women, those who drank one or more cups a day of whole milk had a significantly lower chance of gaining weight than those who drank reduced-fat milk.