The theory that food discount programs could help improve global nutrition is nothing new and one that has been mulled over in several countries; however, new research from the RAND Corporation suggests lowering the costs of healthy foods in supermarkets increases the amount of fruits, vegetables and whole-grain foods that people eat, while also appearing to reduce consumption of nutritionally less-desirable foods.
Researchers examined a program available to members of South Africa's largest private health insurance company that provides a rebate of 10% or 25% on purchases of healthy foods. The program began in 2009 and currently has 800 participating supermarkets and enrolls more than 260,000 households. Shoppers can get the rebate on a list of foods selected by a panel of nutritionists, physicians, and behavioral scientists. That list has more than 6,000 items that account for 20% of food spending at supermarkets. Eligible items are marked at supermarket shelves and include fruits and vegetables, whole grains, nonfat dairy, but excludes most items with added sugars or salt.
The research team collected supermarket scanner data linked to 170,000 households and survey data about diet patterns from 350,000 individuals, including both those who participated in the rebate program and those who did not. Regardless of how the information was analyzed, lower prices for healthy foods were significantly associated with better self-reported diet.
"These findings offer good evidence that lowering the cost of nutritionally preferable foods can motivate people to significantly improve their diet," said Roland Sturm, a study co-author and a senior economist at RAND, a nonprofit research organization. "But behavior changes are proportional to price changes. When there is a large gap between people's actual eating behaviors and what nutritionists recommend, even a 25% price change closes just a small fraction of that gap."
The analysis of supermarket scanner found a rebate of 25% increased the ratio of healthy to total food purchased by 9.3%. The rebate also increased the ratio of fruit and vegetables to total food purchases by 8.5%, and decreased the ratio of less-desirable foods (cookies, candy, chips and soft drinks) to total food purchases by 7.2%. Effects of the price subsidies appeared stable over time and the 25% rebate had consistently greater impact than the smaller rebate.
The research team also analyzed survey responses. Based on self-report, individuals who received a 25% rebate consumed an additional half-serving of fruits and vegetables each day. Those same participants reported being less likely to consume fast food, foods high in sugar and salt, fried foods and processed meats. There was no evidence that the rebate program reduced rates of obesity or that fewer participants were overweight.
