What's the difference between a portion and a recommended serving size?

The difference between a portion and a recommended serving size is as follows:

A portion is the amount of a 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 1 cup of milk. Some foods that most people consume as a single serving actually contain multiple serving sizes (e.g. a 20-ounce soda, or a 3-ounce bag of chips). Nutrition recommendations use serving sizes to help people know how much of different types of foods they should eat to get the nutrients they need. The Nutrition Facts Label on packaged foods also lists a serving size. The serving sizes on packaged foods are not always the same as those included in nutrition recommendations. However, serving sizes are standardized to make it easier to compare similar foods.

This answer is based on source information from the National Heart, Lung and Blood Institute.

Lori Maggioni
Nutrition & Dietetics

A portion is the amount of food that you choose to eat for a meal or snack. On the other hand, a serving size is a specific and measureable amount of food.

A recommended serving size is a standardized unit listed on a product’s nutrition label. It should be the first thing you look at when it comes to label reading. The Nutrition Facts label tells how many servings are in each package, as well as the calories, protein, fat, carbohydrates, sodium, cholesterol, etc. based on that serving size. 

A portion is the amount of that food item actually served or consumed. For example, a serving size of tortilla chips may be 9 chips. If you choose to eat 18 tortilla chips as your portion, you will need to double the information on the nutrition label if you want to know how many calories you’ve had.

Many people are surprised to discover that most 20oz bottled drinks actually have 2.5 servings in them. That is why label reading is so important! Reading the Nutrition Facts label on packaged foods can help you make healthier choices by choosing the right portions.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.