Rebates motivate shoppers to buy produce, whole grains, study says

In discussions of getting people to eat more produce and whole grains, price often comes up as a barrier. Rand Corp. research released Tuesday shows that offering discounts on healthful foods increases the amounts people eat – and it appears also to reduce how much foods such as cookies and chips they eat too.

The researchers looked at a program in South Africa that since 2009 has provided rebates of 10% or 25% to members of Discovery Health, the country’s largest private health insurance company. The program has 800 supermarkets and 260,000 households taking part.

“These findings offer good evidence that lowering the cost of nutritionally preferable foods can motivate people to significantly improve their diet,” Roland Sturm, a study co-author and a senior economist at the nonprofit research organization Rand, said in a statement. “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 Rand study said interest is growing in food discount programs as motivators to improve diet. Nutrient-rich foods have become more expensive, compared with calorie-dense, nutrient-poor foods, and some speculate that this contributes to obesity, the researchers noted. The U.S. Congress funded a demonstration discount project that took place last year in Massachusetts; results are being analyzed.

In the South African program, a list of more than 6,000 items – produce, whole grains, nonfat dairy items -- eligible for rebates was drawn up by nutritionists, doctors and others. Those items are marked on supermarket shelves.

Discovery members could join the program for free, but had to activate it by phone or online. Those who complete an annual survey could increase their discount from 10% to 25%. A family is entitled to a maximum refund of about $125 a month; an individual can get half that.

Sturm noted that the South African program is not an experiment, but an ongoing program and that the participants are similar to insured Americans.

The survey asks questions about eating habits, weight and height. Participants said they ate an average of 3.5 servings of fruits and vegetables a day. The fact that the information is self-reported was cited by the Rand researchers as one shortcoming of their study.

In addition, three-quarters of eligible insured did not take part in the discount program.

There was no evidence that taking part in the discount program reduces obesity.

The researchers from Rand also collected supermarket scanner data linked to 170,000 households. Analysis of that data, published online this month by the American Journal of Preventive Medicine, found that the 25% rebate increased the ratio of healthy to total food purchased by 9.3%.

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