Portion distortion will bust even the best diet. It's how much you eat--more than what you eat--that makes you fat.

Whether you're on a strict low-carbohydrate diet or you're on a do-it-yourself diet that fits your lifestyle, the most important factor for success is portion control. Eat too much of anything and you'll get fat. We have a problem with portion distortion.

If your serving of meat is larger than a cassette tape or your baked potato is bigger than a computer mouse, you're eating too much. Sizing up our favorite foods with commonly used objects is one way to get a better mental picture of how much is the right amount. Plus, it's a lot easier than weighing and measuring your food.

• Three ounces of steak is about the size of a deck of cards or a cassette tape.

• Three ounces of grilled fish is about the size of a checkbook.

• One serving of fresh fruit is about the size of a tennis ball.

• One ounce of cheese is about the size of a C battery.

• One-half cup ice cream is about the size of a tennis ball.

• One cup of pasta, potatoes, or vegetables is about the size of a fist.

• Six ounces of juice is about the size of a yogurt container.

• A two-and-a-half ounce bagel is about the length of a credit card.

• A two ounce muffin is the same size as a small apple.

• One cup of salad is the same size as a baseball.

• One quarter cup of dried fruit, such as raisins, is the size of a golf ball.

• One teaspoon of butter is about the size of the tip of your thumb.

• Two tablespoons of peanut butter is the size of a ping-pong ball.

• One ounce of nuts is one handful.