Consumer Survey: Understanding Portion and Serving Sizes

Consumer Survey: Understanding Portion and Serving Sizes

Download the survey results here


  • Nine in 10 Americans say they have at least some understanding of serving size and portion size.
  • The two terms are often conflated: while nearly half (48%) can correctly define serving size, the same percentage incorrectly associates the definition for portion size with that of serving size.
  • Regardless of food or beverage category, about half say they try to eat close to the serving size listed on packaging.
  • The top-ranked reasons for paying attention to portion sizes are to help control weight (36% ranked in top 2) and to help avoid eating too much of certain foods (30%).

You’ve likely witnessed someone turning over a packaged food to look at the serving size on the Nutrition Facts label with surprise. They’ve probably also said something along the lines of, “is this really how much I’m supposed to eat?” – or maybe you’ve experienced this yourself.

But do Americans really know what the purpose of the serving size on the Nutrition Facts Label is, and how it differs from the concept of portion size? How exactly do Americans use serving and portion size, and what are their reasons for wanting to manage how much food they eat? This survey aimed to explore Americans’ understanding of both serving and portion size.

Key Findings:

  • Despite the majority saying that they have an understanding of portion and serving size, there is a clear knowledge gap. Ninety-one percent said that they had at least some understanding about serving size; 90% said the same about portion size. However, when given a list of possible definitions for both serving and portion size and asked to select the two that best align with their understanding, the confusion between the two terms became apparent.

Of those who claimed knowledge of serving size, almost half (48%) picked the correct definition for the term, which is the standardized amount of a food or beverage that people typically consume in one sitting. Slightly fewer (46%) thought it was defined by the company that created the product. Of those who claimed knowledge of portion size, the most selected definition for the term was actually the definition for serving size. However, this was closely followed by the correct definition – the amount one chooses to eat in one sitting (45%).

  • Providing even a basic description of serving and portion size proves to be educational. When respondents were shown complete definitions of both terms and asked how their understanding had changed as a result, about one-third (34%) said that they understood much more, followed by 30% who said they understood somewhat more.
  • Although serving sizes are not recommendations for how much to eat, many use them for this purpose. When asked about how often they purposefully try to eat close to the serving size listed on the package, about half said they frequently or sometimes do, regardless of food or beverage category. What’s more, 44% said they’d look to the serving size on food packaging as a source of information on portion sizes.
  • Americans control their portion sizes in a variety of ways. Helping to control weight (36%), helping to avoid eating too much of certain foods (30%) and helping to know how much they should be eating or drinking (26%) were the top-ranked reasons for paying attention to portion size. Those who pay attention to portion sizes deploy a variety of strategies to manage them, ranging from trying to eat more slowly to limiting distractions while eating. Nearly one in three said they use smaller plates or bowls to reduce portion size (32%) and choose single-size portions (31%).

However, one in 6 survey respondents reported that they don’t pay attention to portion sizes, with people over the age of 45 and those earning less than $40,000 per year being more likely to say this, compared to their counterparts. When asked about why they don’t, nearly three-quarters (71%) said they don’t want to be too restrictive on how much they eat or drink. One-third (33%) said it is more important not to waste food than to have the right portion size.


Survey results were derived from online interviews of 1,000 adults conducted from November 4 to November 9, 2021, by Lincoln Park Strategies. They were weighted to ensure proportional representation of the population, with a margin of error of ±3.1 points at the 95% confidence level.