30. AVOID WHITE FOODS.

There is some scientific legitimacy to today’s lower-carb diets: Large amounts of simple carbohydrates from white flour and added sugar can wreak havoc on your blood sugar and lead to weight gain. While avoiding sugar, white rice, and white flour, however, you should eat plenty of whole-grain breads and brown rice. One Harvard study of 74,000 women found that those who ate more than two daily servings of whole grains were 49 percent less likely to be overweight than those who ate the white stuff.