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Portion Distortion and Serving Size

Portions and Servings: What’s the Difference?

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

A 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 (typically consumed as one portion), and you’ll see that it has 2.5 servings in it. A 3-ounce bag of chips—which some would consider a single portion—contains 3 servings.

For a look at recommended serving sizes, check out the NHLBI Serving Size Card pdf icon(119 KB). For help using the Nutrition Facts label, visit the U.S. Food and Drug Administration Web site.

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. These 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 growing 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 eye-opening examples, check out NHLBI's Portion Distortion Web site. Or, take the printable version of the Portion Distortion Quiz pdf icon (637 KB, Download Adobe Reader).  

Last Updated: May 8, 2012

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