As rates of obesity continue to rise in much of the developed world, so does the urgency to improve people's food choices. Researcher Dr. Cliona Ni Mhurchu of the University of Auckland in New Zealand and her team conducted a six-month trial across eight supermarkets to determine the effects of two strategies: price discounts and nutrition education.
A total of 1,104 shoppers were randomized to receive a price discount on healthy foods, tailored nutrition education, a combination of the two or no intervention. Healthy foods were 12.5 percent cheaper for those randomized to receive discounts. Participants in the nutrition education group received monthly packages of food-group-specific information tailored to their shopping history. All supermarket purchases were recorded with handheld barcode scanners.
According to a report in the American Journal of Clinical Nutrition, after six months of intervention, participants receiving price discounts bought approximately 1.7 more pounds of healthy food per week compared with those not randomized to pay the lower prices.
This was an 11 percent increase from purchases made prior to the study and included just over a pound more fruits and vegetables per week or about six servings. The total difference dropped to around 0.8 pounds, but remained significant, six months after the study was over. No consistent differences were found between the groups in the amounts of purchased saturated fat or other nutrients.
Study participants were generally more informed and interested in healthy eating than average individuals. Nutrition enthusiast or not everyone likes a bargain. The price reductions may have provided an additional incentive over health to buy healthier foods. Although these reductions didn't change the quantity of unhealthy food purchased, almost two thirds of the additional healthy purchases were fruit and vegetables.