What is the difference between a serving and a portion?
The U.S. Food and Drug Administration (FDA) Nutrition Facts label appears on most packaged foods (see Figure 1). It tells you how many calories and servings are in a box or can. The serving size varies from product to product.
A portion is how much food you choose to eat at one time, whether in a restaurant, from a package, or at home. Sometimes the serving size and portion size match; sometimes they do not.