Carbohydrate claims can mislead consumers, study finds

In the early 2000s, low-carbohydrate claims gained huge popularity in response to such books as Dr. Atkin's New Diet Revolution and The South Beach Diet. In a study published in AC Nielsen Consumer Insights, it was noted that there was a 516% sales increase in low-carbohydrate food products from 2001 to 2005 showing that front of package claims can play a large part in consumer decisions.

Existing research suggests that consumers are less likely to turn to the back of a package to look at the Nutrition Facts panel when there is a claim on the front of the package. In the new study, researchers at the United States Food and Drug Administration, Center for Food Safety and Applied Nutrition sought to determine whether low-carbohydrate claims might lead consumers to perceive products to have benefits that are not necessarily related to being low in carbohydrate. Using an online questionnaire, 4,320 consumer panelists rated products for their perceived healthfulness, helpfulness for weight management, and caloric content based on front-of-package-only conditions (nutrition claims versus no nutrition claims) and availability of Nutrition Facts panels.

This study documents that in the absence of Nutrition Facts panels, "low-carbohydrate claims led to more favorable perceptions about products' helpfulness for weight management, healthfulness, and caloric content. Because an individual packaged food product's usefulness for weight management as part of an overall diet, its healthfulness, and total calorie content are not dependent solely on the amount of total carbohydrate it contains, the study demonstrated that consumers could misattribute benefits to products that claim to be low in carbohydrate."

However, the researchers found that when the Nutrition Facts panels are available "participants' perceptions became more consistent with the nutrition profile of the products…By showing the claims and the NF [nutrition facts] side-by-side, both pieces of information were equally accessible to participants as they answered the study questions. The presence of the NF, however, allowed participants to use this more diagnostic information to judge the product."

One limitation mentioned in this study by Dr. Judith Labiner-Wolfe, former consumer science specialist at the United States Food and Drug Administration (now an evaluation specialist at the United States Department of Health and Human Services' Office on Women's Health) and colleagues is that "the online venue for viewing the stimuli and answering the study questions may have fewer distractions than situations in which consumers make real product judgments, such as in a busy grocery store. Therefore, this study may overestimate the effect of the Nutrition Facts panel. Findings from this research are consistent with previous experimental studies that found participants misattribute health benefits to products with claims and that nutrition information has an independent effect on perceptions." The authors' state, "although exposure to the Nutrition Facts has the potential for mitigating inappropriate benefits attributed to products claiming to be low carbohydrate, previous consumer research suggests that when a food product carries a front-of-package claim, consumers are less likely to turn the package over to look at the Nutrition Facts panel."

Within the article, the researchers emphasize the important role nutrition educators have in helping consumers better understand the limited meaning of front- of- package claims and to further emphasize the importance of using the Nutrition Facts panel when making food choices.

The article is "Effect of Low-carbohydrate Claims on Consumer Perceptions about Food Products' Healthfulness and Helpfulness for Weight Management" by Judith Labiner-Wolfe, PhD; Chung-Tung Jordan Lin, PhD; and Linda Verrill, PhD. It appears in the Journal of Nutrition Education and Behavior, Volume 42, Issue 5 (September/October 2010) published by Elsevier.