A diet should be rich in vegetables, fruits, whole grains, and legumes and low in refined grains, sugary foods, and saturated and trans fats.
Make sure that you include fish, poultry, and other lean meats; dairy foods (low-fat or nonfat sources are preferable to save calories).
You should aim for 20 to 35 grams of fiber a day from plant foods, since fiber helps fill you up and slows absorption of carbohydrates.
Check out the the USDA’s MyPlate, which recommends filling half your plate with vegetables and fruits. Grains (preferably whole grains) and protein foods should each take up about a quarter of the plate.