The American Diabetes Association recommends the following analogy as a way of measuring one serving of a certain food:
• A 1/2-cup serving of canned fruit, vegetables, or potatoes looks like half a tennis ball.
• Three ounces of meat, fish, or chicken is about the size of a deck of playing cards or the palm of your hand.
• A 1-ounce serving of cheese is about the size of your thumb.
• A 1-cup serving of milk, yogurt, or fresh greens is about the size of your fist.
• One teaspoon of oil is about the size of your thumb tip.