Trying to eat healthy? Read those nutrition labels carefully

People who made New Year’s resolutions to eat healthier or lose weight might also want to brush up on their math skills.

In a new study, marketing professor Donald Lichtenstein found that nutrition labels on packaged food products in the United States can lead even the most health-conscious consumers astray, if they don’t “do the math.”

While the “Nutrition Facts” printed on food labels are regulated by the Food and Drug Administration, companies are given some freedom to present food packages as a single serving or as smaller serving sizes within a package, according to Lichtenstein, chair of the Leeds School marketing department. Through this practice, referred to in the study by Lichtenstein and his colleagues as “health framing,” companies can present smaller serving sizes so that a food’s negative nutrients -- calories and fat -- on a nutrition label show up as a lower number per serving.

“The take-away message is when you look at the calories per serving on a candy bar or a can of soup at the grocery store, be sure to look at the serving size too,” Lichtenstein said. “Surprisingly, what we found was those people who are health conscious and are concerned about nutrition fall prey to health framing effects more frequently.

“The problem comes when people do pay attention, but they only pay attention to the calorie information and not the serving size,” Lichtenstein said. “And that’s what we find in study after study. Those consumers who are more health conscious pay attention to the calorie information, but they don’t take the extra step to look at the serving size. So they are duped, if you will, by a health framing effect.”

This is where the math part comes in. For example, if a candy bar is 2 ounces and has 200 calories for a whole bar, it might be labeled as one serving or two servings. If the manufacturer decides to make the serving size of 1 ounce it cuts the calories per serving in half.

“We found that many consumers only pay attention to the calorie information and don’t look to see exactly what the serving size is,” he said. “When you present a smaller serving size, it cuts down the calories per serving, which makes consumers feel less guilty about consuming the product, and that affects not only their purchase intentions, but actual choice."

To ensure more informed consumer choices, Lichtenstein recommends reducing the latitude manufacturers have in setting serving sizes, requiring manufacturers to report nutrient information on a per unit weight basis -- calories per ounce -- and increasing consumer education about manufacturer use of health framing.

Without any changes to policy, Lichtenstein said, consumers need to put the onus on themselves when it comes to food labels.

“In the absence of any changes, public policy officials should encourage consumers to calculate negative nutrients for a reasonable serving size, so they know the health benefits and detriments of the foods they eat,” Lichtenstein said.