UNC Gillings School Study: 'No Fat,' 'No Sugar' no guarantee of nutritional quality

March 15, 2017

Terms such as “no fat” or “no sugar” on food packaging may give consumers a sense of confidence before they purchase, but these claims rarely reflect the actual nutritional quality of the food.

These are the findings of a new study led by researchers at The University of North Carolina at Chapel Hill. The study, “No Fat, No Sugar, No Salt . . . No Problem? Prevalence of “Low-Content” Nutrient Claims and Their Associations with the Nutritional Profile of Food and Beverage Purchases in the United States,” was published online March 15 in the Journal of the Academy of Nutrition and Dietetics.

The study’s findings indicate that, because many claims are made relative to similar products instead of based on absolute nutritional content, such claims do not always offer consumers an accurate indication of the food’s general healthfulness. For example, a three-cookie serving of “reduced-fat” Oreos contains 4.5 grams of fat, compared to seven grams in a serving of full-fat Oreos, but both still contain 14 grams of sugar per serving. In some cases, foods with “low,” “reduced” or “no” nutrient claims actually had a worse overall nutrient profile than those without claims.

Dr. Lindsey Taillie

Dr. Lindsey Taillie

“Our results demonstrate that for packaged foods and beverages, purchases featuring ‘low’ or ‘reduced’ nutrients claims do not necessarily offer the better overall nutrition implied by the claim,” explained lead investigator Lindsey Smith Taillie, PhD, research assistant professor in the Department of Nutrition at UNC’s Gillings School of Global Public Health. “This is likely due in part to ‘reduced’ claims only being relative within brands or specific food categories, while ‘low’ claims are relative to portion size.”

Taillie and her fellow researchers undertook the study to better understand what effects low-content packaging claims had on purchasing habits, as well as what relationship they had to the actual nutritional content of foods. The research examined data that included more than 80 million food and beverage purchases from more than 40,000 households. They found that 13 percent of food and 35 percent of beverage purchases had a low-content claim, including “no,” “free,” “low” or “reduced.”  In addition, “low-fat” was the most common claim, followed by “low-calorie,” “low-sugar” and “low-sodium.” While the data revealed that products with some sort of claim had lower mean energy, total sugar, total fat and sodium densities, they did not always represent the best nutritional value.

Because there is, for example, no agreement about what constitutes “reduced-sugar” cookies, researchers say consumers need to be cautious. A cookie marked “reduced-sugar” may contain less sugar than that brand’s “regular” version, but still may not contain less sugar than other cookies.

Foods with a “low” claim, on the other hand, are permitted to have a set amount of that nutrient per portion size—but because portion sizes can vary across food categories, it still can be challenging to use this type of claim to make assessments about whether a food or beverage is a more healthful choice.

Regardless of the specific type of claim, a food with any nutrient-specific claim still could be worse in regard to other nutrients.  For example, a “low-fat” cookie could have higher energy, fat or sodium than do other cookies.

“In other words, ‘low-,’ ‘reduced-‘ or ‘no-‘ nutrient claims mean different things for different foods,” said Taillie. “This can produce confusion if consumers are seeking out products with specific nutrient claims or are using a claim to justify the purchase of food. In fact, the data suggest that in some cases, products that tend to be high in calories, sodium, sugar or fat actually may be more likely to have low-, reduced- or no-content claims.”

While the study focused on whether these claims had any connection to the actual nutritional value of the food and beverage items, investigators also looked at the groups of people who were more likely to purchase foods that made these statements. They found that while differences in purchasing patterns by race/ethnicity were not significant, non-Hispanic white households were most likely to buy products with a “low-calorie” claim and Asian households preferred foods with “low-fat” or “low-sodium” claims. Non-Hispanic black households were least likely to purchase food groups with any low-content claim.

There was also a connection between socioeconomic status (SES) and food purchases. Researchers found that high- and middle-SES households were more likely to purchase food and beverages with low-content claims.

Even though a large sample size was used for the study, Taillie reports that the research is not conclusive and that more investigation needs to be done.

“A key question for future research will be to examine how these claims affect consumer choice, as well as how claims interact with other common strategies, such as sales or price promotions, to influence purchasing behavior and ultimately, dietary quality,” Taillie said.

The full study can be found here.

This work was conducted at the UNC-Duke U.S. Department of Agriculture Center for Behavioral Economics and Healthy Food Choice Research and funded by Healthy Eating Research, a national program of the Robert Wood Johnson Foundation.


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Gillings School of Global Public Health contact: David Pesci, director of communications, (919) 962-2600 or dpesci@unc.edu