Portions and servings: What’s the difference?

portion is the amount of food that you choose to eat for a meal or snack. It can be big or small, you decide.

serving is a measured amount of food or drink, such as one slice of bread or one cup (eight ounces) of milk.

Many foods that come as a single portion actually contain multiple servings. The Nutrition Facts label on packaged foods, on the backs of cans, sides of boxes, etc. tells you the number of servings in the container.

For example, look at the label of a 20-ounce soda (usually consumed as one portion). It has 2.5 servings in it. A 3-ounce bag of chips, which some would consider a single portion, contains 3 servings.

Look at serving sizes on the nutrition label.  resources. Click on the National Heart, Lung, and Blood Institute’s Serving Size Card (119 KB) for examples. For help using the Nutrition Facts label, download our How to Use the Nutrition Facts Label tip sheet (107 KB) or visit the U.S. Food and Drug Administration website.

Portion Distortion

Average portion sizes have grown so much over the past 20 years that sometimes the plate arrives and there’s enough food for two or even three people on it. Growing portion sizes are changing what Americans think of as a “normal” portion at home too. We call it portion distortion.

Check out these examples of how larger portions lead to increased calories:


Comparison of Portions and Calories 20 Years Ago to Present Day
20 Years Ago Today
 Portion  Calories  Portion  Calories
Bagel 3” diameter 140 6” diameter 350
Cheeseburger 1 333 1 590
1 cup sauce
3 small
500 2 cups sauce
3 large
Soda 6.5 ounces 82 20 ounces 250
1.5 ounces 210 5 ounces 500


For more examples, go to the NHLBI Portion Distortion page. Or, take the printable version of the Portion Distortion Quiz (637 KB).


Source: National Heart, Lung, and Blood Institute; National Institutes of Health; U.S. Department of Health and Human Services.