Try to limit the amount of carbohydrates, such as potatoes, peas, butternut squash, rice or pasta, to a quarter of your plate (about 1 cup).The healthiest carbohydrates come from fruits, vegetables, beans, legumes, and whole grains. Whole grains contain three components: the fiber-rich outer bran, the nutrient-rich central germ, and the starchy middle layer (endosperm).