How Is The Serving Size Determined On Food Nutritional Labels In The US?

Decoding the labels on food products can sometimes feel like reading a foreign language. Depending on the product, you may learn varying information –- labels can tell us if we're getting vanilla extract alternatives, extra sugar added to our yogurt, or incomplete whole grains. Nutritional info also shows you what percentage of the daily value of a certain nutrient you're getting, so you can avoid going over the daily suggested amount. For example, the U.S. Food and Drug Administration (FDA) recommends no more than 2,300 mg of sodium per day for adults. That sounds like a lot, but it's the equivalent of only one teaspoon of table salt!

The serving size is an added layer to consider when reading labels. According to the American Heart Association, serving size is the standardized amount of food listed on a nutrition label. So when you're reading the nutritional info for an item, the quantities and percentages listed apply only to the serving size. The label will also usually indicate the number of servings per container –- for example, if a can of soup says it has 300 mg of sodium, but four servings per container, consuming the whole can would give you 1,200 mg of sodium in total.

While serving sizes can be helpful, as not everyone will eat a whole can of soup at once, they can also be confusing, as many people mistake the serving size for the recommended amount for consumption.

According to Food Insight, about half of Americans try to eat close to the serving size listed on nutritional labels. But while limiting portions can be beneficial, serving sizes aren't intended to tell you how much you should eat. According to the National Library of Medicine, the Nutrition Labeling and Education Act of 1990 dictated that serving sizes be calculated from the amounts of food most commonly consumed. The information used to determine those quantities is gleaned from national food intake surveys and data from the United States Department of Agriculture (USDA) and given to the FDA. Serving sizes are also updated to reflect changes in the American diet, with many of them increasing; for example, the serving size for most sodas has changed from 8 fluid ounces to 12 fluid ounces (via FDA).

Many people get confused when mistaking serving size for portion size. According to the American Heart Association, portion size is the actual amount of food you eat, which is why you may see a variety of diets talking about recommended portion sizes. GoodRx Health notes that over the years, American portion sizes, meaning the amount of food we think is normal to eat, have steadily increased.

So the next time you read a nutritional label, keep in mind that the serving size is not necessarily the most beneficial amount to consume. To figure out your ideal portion size, do some research from reputable sources, or talk to a nutritionist or dietician.