The Mediterranean diet isn’t the only fat-busting import from Europe. Following a Baltic Sea diet may help keep your belly flat, reports a study in the British Journal of Nutrition. Men who ate the traditional Scandinavian fare – lots of cereal grains, berries, vegetables, low-fat milk and fish – were 43% less likely to have waists larger than 238cm than men who didn’t eat that way. The fibre in grains like oats and barley keeps you full longer, reducing overeating, says study author Noora Kanerva. The slimmest people in the study averaged 117g of these grains a day, equal to ½ cup of cooked oats.