Is the current definition of serving size is the amount of food customarily eaten at one time?

November 17, 2025 •

3 min read

In 2016, the FDA updated its nutrition facts label guidelines to reflect more realistic consumption habits. The current definition of serving size is the amount of food customarily eaten at one time, as determined by national food consumption surveys, not a dietary recommendation. This change aims to provide more accurate nutritional information based on what people actually eat and drink.

Quick Summary

The FDA defines serving size as the amount of food or drink typically consumed in one sitting, using data from national surveys. This metric, known as Reference Amount Customarily Consumed (RACC), forms the basis for the nutrition label and is distinct from a personalized portion size, which is how much a person chooses to eat. Updates to the nutrition label, based on recent consumption data, have adjusted some serving sizes to better reflect current eating behaviors.

Key Points

Based on Customary Intake: Serving sizes are determined by the FDA using national food consumption surveys to reflect how much people typically eat in one sitting, not what they should eat.
Reference Amounts Customarily Consumed (RACC): The FDA uses these standardized amounts, derived from survey data, as the foundation for setting serving sizes for all food categories.
Serving Size vs. Portion Size: A serving size is a regulated, static amount on a nutrition label, while a portion size is the variable amount an individual chooses to eat.
Recent Label Updates: The 2016 nutrition label changes led to updated serving sizes, with some increasing (like ice cream) to reflect current eating habits, and featured larger, bolder text for key information {Link: azulcorawellness.com https://azulcorawellness.com/blog/serving-sizes-misleading-and-fail-to-do-this-one-thing}.
Dual-Column Labels: For packages that could be consumed in one or multiple sittings, labels now include two columns showing nutrient information per serving and per package.
Helps Compare Products: Standardized serving sizes allow consumers to compare the nutritional value of similar products more easily.
Influences Portion Choice: Exposure to larger labeled or restaurant serving sizes can influence personal perceptions of what is a "normal" portion, potentially leading to increased consumption.

The Core Principle: A Reflective, Not Prescriptive, Measure

The current serving size definition reflects the amount of food people customarily eat, based on national consumption surveys. This data-driven approach, utilizing Reference Amounts Customarily Consumed (RACC), forms the basis for the serving sizes set by the U.S. Food and Drug Administration (FDA). Updates influenced by consumption data have led to changes on nutrition labels, with some serving sizes adjusted to align with modern eating habits.

How the FDA Determines Serving Size

The FDA uses a standardized process based on RACC values to set serving sizes for different food categories. This process considers various product formats. Serving sizes for discrete units are based on the number of units approximating the RACC, while bulk foods use household measures closest to the RACC. Single-serving packages (150%-200% of RACC) are labeled as one serving, and dual-column labels are required for packages between 200% and 300% of the RACC to show per serving and per package information {Link: azulcorawellness.com https://azulcorawellness.com/blog/serving-sizes-misleading-and-fail-to-do-this-one-thing}.

The Crucial Distinction: Serving Size vs. Portion Size

Understanding the difference between serving size and portion size is vital for informed dietary choices. Serving size is defined by the FDA based on RACC for standardization, while portion size is determined by the individual based on personal appetite. Serving size is static and regulatory, whereas portion size is variable. Serving size provides a reference for calculating intake, while portion size directly impacts calorie intake and is often larger than the serving size. For example, one serving of ice cream is 2/3 cup, but a person may scoop more.

Comparison of Serving Size and Portion Size


Feature	Serving Size	Portion Size
Defined By	The FDA based on RACC.	The individual.
Purpose	To provide a standardized metric for comparison.	Reflects personal appetite and habits.
Flexibility	Static and regulatory.	Variable.
Impact on Health	Provides a reference for calculating intake.	Directly influences calorie intake; often larger than serving size.
Example	One serving of ice cream is 2/3 cup.	Amount a person actually scoops, which can be more.

The Evolution of Serving Sizes and Consumption

Updated serving sizes in 2016 acknowledged changes in American eating habits, including larger restaurant portions and increased overall consumption. This "portion distortion" can impact perceptions of normal eating amounts, potentially leading to overconsumption. Research indicates that larger package or portion sizes can influence how much people serve and eat. The updated labels with bolded text for "Serving Size" and "Calories" aim to make this information more noticeable.

Practical Application of Serving Size

Consumers should use the nutrition facts label, including "servings per container," to understand their actual intake, especially with packages containing multiple servings. Dual-column labels help by showing nutrient information for the whole package. Learning visual cues for estimating serving sizes can also assist with portion control.

The Implications for Public Health

Basing serving sizes on customary consumption offers a realistic baseline for intake assessment, but also highlights the difference between typical eating habits and dietary recommendations. Nutritional education is important to help consumers make healthier choices, rather than being swayed by package or portion size. Public health strategies could include clearer labeling and smaller package options to help manage consumption.

Conclusion

Yes, the current definition of serving size is the amount of food customarily eaten at one time. This definition is regulatory, based on national survey data, and not a dietary recommendation. The distinction between serving size and portion size is crucial for managing dietary intake. By understanding how serving sizes are determined and how environmental factors influence portion choices, consumers can make more informed decisions for their health {Link: azulcorawellness.com https://azulcorawellness.com/blog/serving-sizes-misleading-and-fail-to-do-this-one-thing}. Food labeling evolves with eating habits, and consumer awareness is key to using this information for a healthier lifestyle.

Serving Size on the Nutrition Facts Label - FDA

Frequently Asked Questions

The U.S. Food and Drug Administration (FDA) defines the official serving sizes for packaged food based on nationwide food consumption data.

No, a serving size is a standardized, regulated amount on a nutrition label, while a portion size is the amount of food an individual chooses to eat.

In 2016, the FDA updated serving sizes to reflect more current consumption data, increasing some (like for ice cream) and decreasing others (like for yogurt) to better match what people actually eat {Link: azulcorawellness.com https://azulcorawellness.com/blog/serving-sizes-misleading-and-fail-to-do-this-one-thing}.

RACCs are standardized amounts of food that people typically eat in one sitting, used by the FDA to calculate serving sizes for different food products.

Knowing the difference is crucial for managing your calorie and nutrient intake, as your portion may be larger than the labeled serving size, leading to overconsumption if not accounted for.

Dual-column labels, for packages containing more than one serving, display nutritional information per serving and per package, making it easier to see total calories if you eat the whole thing.

No, the serving size on the label is not a recommendation for how much you should eat, but a reference point for the nutritional information.