Here is some helpful information, visuals, regarding serving sizes:

• Two cups of mixed greens are two baseballs.
• One cup of raw vegetables is a baseball.
• A half cup of cooked vegetables, rice, cereal, couscous, bulgur wheat, beans, tofu, or low-fat cottage cheese is a cupcake or muffin.
• One medium baked potato or sweet potato is a computer mouse.
• For vegetable or fruit juice, 8-10 ounces is about three-quarters of a soda can.
• One medium piece of raw fruit is a tennis ball.
• One cup of berries or chopped fruit is a baseball.
• A fourth of a cup of dried fruit is a golf ball.
• A half of a whole-grain 3-ounce bagel, a half of a whole-wheat English muffin, or a half of a whole-grain hamburger bun is a hockey puck.
• One whole-wheat pita or one whole-wheat flour or corn tortilla is an average-sized saucer.
• Four whole-grain crackers are four tea bags.
• Two low-fat whole-wheat pancakes are two compact discs.
• One cup of milk (skim, low-fat, 1 percent, soy, rice, and nut milks) or one cup of plain, low-fat, sugar-free, or soy yogurt, is a baseball.
• An ounce of hard cheese is a tube of lipstick.
• One vegetarian burger or patty is a lid to a mayonnaise jar.
• One tablespoon of oil (olive, canola, flaxseed, peanut, sesame, walnut, or other oil), salad dressing, mayonnaise, nut butters, nuts, or seeds is one checker.
• When it comes to meat, I recommend 4 ounces—roughly the same size as your checkbook or a deck of cards—as part of a healthy meal.