A nudge in a healthy direction. The effect of nutrition labels on food purchasing behaviors in university dining facilities.

Background: Despite legislation that requires restaurants to post nutritional labels on their products or menu items, the scientific literature provides inconsistent support for the idea that adding labels to foods will change buying patterns. Lack of success of previous research may be that sample sizes have been too small and durations of studies too short.

Objective: To assess the effect of nutrition labeling on pre-packaged food purchases in university dining facilities.

Design: Weekly sales data for a sample of pre-packaged food items were obtained and analyzed, spanning three semesters before and three semesters after nutritional labels were introduced on to the sample of foods. The labels summarized caloric content and nutrient composition information. Mean nutrient composition purchased were calculated for the sample of foods. Labeled food items were categorized as high-calorie, low-calorie, high-fat, or low-fat foods and analyzed for change as a function of the introduction of the labels.

Setting: Data were obtained from all retail dining units located at Cornell University, Ithaca, NY where the pre-packaged food items were sold.

Results: Results indicated that the introduction of food labels resulted in a 7% reduction of the mean total kcals purchased per week (p < 0.001) from the labeled foods. Total fat purchased per week were also reduced by 7% (p < 0.001). Percent of sales from "low-calorie" and "low-fat" foods (p < 0.001) increased, while percent of sales from "high-calorie" and "high-fat" foods decreased (p < 0.001).

Conclusions: The results suggest that nutrition labels on pre-packaged foods in a large university dining hall produces a small but significant reduction of labeled high calorie and high fat foods purchased and an increase in low calorie, low fat foods.