A package that says “low sodium,” “high protein” or “sugar free” is giving you useful information. But it isn't necessarily telling you whether the product is nutritious overall.
That's the message from a new analysis of nearly 150,000 packaged foods and beverages introduced in the United States over a 10-year period. Published in Nature Food, researchers found that products with nutrition and health-related claims often compared favorably with products without them. But there were plenty of exceptions, and a claim about one nutrient didn't necessarily reflect what was happening with the rest.
In other words, the claim may be completely accurate. It just isn't the whole story.
Researchers from Cornell University and the University of Kentucky analyzed 145,609 new packaged foods and beverages introduced from 2015 through 2024. They looked at dozens of common package claims, including “sugar free,” “low sodium,” “high protein,” “whole grain,” “organic” and claims related to probiotics and other potential health benefits.
They then used a nutrition scoring system that considers several parts of a food at once, including sugar, sodium, saturated fat, fiber and protein. That allowed them to look beyond the particular feature advertised on the package.
For most foods, products carrying claims actually scored better overall than products without them. That's an important distinction because the findings don't suggest that nutrition claims are generally deceptive or that foods carrying them are less nutritious.
Instead, researchers found that the picture changed depending on the product and the claim.
Beverages offered some of the clearest examples. Drinks labeled low or reduced in sodium sometimes had less favorable overall nutrition scores than drinks without those claims. When researchers looked more closely, higher sugar levels helped explain the difference in several beverage categories.
Some foods labeled low or reduced in trans fat showed a similar pattern. Depending on the type of food, products carrying the claim also tended to have higher levels of saturated fat or sodium.
That doesn't mean manufacturers removed one ingredient and replaced it with another. The study wasn't designed to determine why products were formulated as they were. It simply found that improving or highlighting one nutritional characteristic didn't guarantee that every other characteristic would also be favorable.
“One day I went to a supermarket, and I noticed there was original flavor and lower-fat cream cheese,” said study author Pei Zhou. “They had reduced the fat, but they had more total sugars and more sodium. There are so many label claims on packages. Our main question was whether products with claims are healthier than those without health claims.”
The researchers also examined labels such as “organic,” “whole grain” and “GMO-free.” Those descriptions can provide meaningful information about ingredients or how a food was produced, but they aren't designed to summarize its sugar, sodium, saturated fat or other nutritional characteristics.
That's where something known as the “health halo” can come into play. Previous research has found that consumers may see one positive characteristic and assume the product is healthier overall, even when the claim doesn't provide that information.
The new study doesn't show how individual shoppers respond to these labels. Researchers analyzed products and their nutrition information, not people's shopping decisions. But the findings help illustrate why relying on a single claim can leave out important context.
There are other limitations. The researchers used a nutrition scoring system developed in the United Kingdom, not the system the U.S. Food and Drug Administration uses to regulate food claims. The study also looked specifically at newly introduced packaged products rather than everything available in American grocery stores or what Americans actually buy.
Those distinctions make the study less of an indictment of food labels and more of a reminder about what they can and can't tell you.
“We provide some direction for policymakers in our paper,” said study author Miguel Gómez. “The general idea is to transition from single claims to a broader nutrient profile style. In countries like Chile or Mexico, they use traffic stop signs to warn consumers about high salt, sugar and fat, and this limits the positioning of products in the supermarket.”
For shoppers, that doesn't mean ignoring claims on the front of the package. If you're looking for a product with less sodium, more fiber or another particular characteristic, those labels can be helpful. But checking the Nutrition Facts label can provide the broader context that a single claim can't.
One researcher received support from the U.S. Department of Agriculture's National Institute of Food and Agriculture. Publication support came from Cornell University's Food Industry Management Program and Cornell Atkinson Center for Sustainability. Another researcher received support from the Cornell SC Johnson College of Business.