Can "Low Fat" Nutrition Labels Lead to Obesity?
Dr. Brian Wansink, director of the Cornell Food & Brand Lab. and Dr. Pierre Chandon, assistant professor of Marketing at INSEAD, developed and tested a framework that contends that "low fat" labeling increases food intake by 1) increasing perceptions of the appropriate serving size and 2) decreasing consumption guilt.
Study 1 examined whether "low fat" nutrition labels increase the actual and estimated consumption of a hedonic food (chocolate candies) among overweight and normal weight consumers. The study enlisted 269 participants, all of whom were incoming students and their families who were visiting a university open house. Participants were presented with two large bowls of M&Ms, one bowl labeled as "low fat M&Ms" and the other labeled as "regular M&Ms", and asked to serve themselves as much as they liked. Their bowls were then weighed and they were asked to fill out a questionnaire that included calorie estimation and demographic information questions. The results showed that participants ate 28.4% more of the M&M's labeled "low fat" than of the M&Ms labeled"regular". Also, overweight participants served 16.7% more M&M's than normal weight participants. This study supported the hypothesis that low–fat nutrition claims increase consumption and confirmed that overweight people eat more than normal weight people when a food is labeled "low fat" than when it is labeled "regular."
Study 2 addressed what we believe to be an appropriate serving size when a food is labeled "low fat" vs. when it is labeled as a "regular" food. Hedonic foods (M&Ms) and more utilitarian foods (granola) were used. The study enlisted 74 adults on a major university campus. Half of the participants were assigned to "regular" foods and the other half was assigned to "low fat" foods. Participants were given containers of either regular or low fat M&M's and granola, and asked to indicate how much of each food would be appropriate to eat during a 90 minute movie. Participants assigned to the low fat food believed the appropriate serving size was 25.1% larger than those assigned to the regular version of the same food. In addition, all participants indicated that they would feel less guilty eating low fat foods than the regular food. These results show that low fat foods increase the perception of appropriate serving size and make people feel less guilty about their consumption volume.
Study 3 tested whether or not providing objective serving size information can help prevent people from overeating foods labeled "low fat". Two hundred and ten undergraduates at a major university were enlisted in the study. Participants viewed a 60 minute television program and were given granola in zip lock bags, labeled as either "regular" or "low fat" granola. Furthermore, the bags were labeled as containing either 1 serving or 2 servings. The results of this study were consistent with those in study 1 and study 2. Furthermore, they showed that providing salient information on serving size reduces overeating among guilt–prone, normal weight consumers but not among overweight consumers.
On the basis of these results the authors identify key packaging and labeling insights for both public policy officials, food manufacturers and researchers.
Download a pre-print version of this article here. Reprinted with permission from Journal of Marketing Research, published by the American Marketing Association.
*The study was conducted at the University of Illinois, former location of the Cornell Food and Brand Lab.