Discounts could influence healthy choices more than education

The food and beverage industry has been under increasing pressure from consumers and governments to play a role in encouraging healthy eating. It has stepped up with a variety of measures, including education campaigns, while taxes and price incentives have also been put forward as possible solutions to health problems associated with poor dietary choices, such as obesity, hypertension and type-2 diabetes.

The researchers behind this latest study found that neither price discounts nor tailored nutrition education had a significant effect on the amount of saturated fat purchased or the purchase of any particular nutrients among a group of 1,104 New Zealand shoppers.

However, the overall quantity of healthy foods purchased by those randomly assigned to receive a 12.5 percent price discount was significantly higher six months into the study, at 0.79kg per week, they said, a 10 to 11 percent increase in purchases compared to the beginning of the program. In addition, those effects were sustained at 12 months, “showing an effect on food purchasing behavior that persisted after cessation of price discounts.”​

Healthy foods for price discounts and nutrition education were selected for the study on the basis of the New Zealand Heart Foundation’s Tick program​ nutritional standards.

In contrast, the researchers found no effect on food purchases as a result of “carefully tailored nutrition education”, ​also based on the Tick program’s standards.

The study’s subjects were mostly women, in order to reflect their higher likelihood to be primary household shoppers, and came from households with a range of income levels. However, the authors noted that the study’s participants were perhaps better educated that the overall population, with 85 percent rating their knowledge of nutrition and healthy eating as ‘moderate’ or ‘a lot’.

Applying commercial expertise​

Despite a lack of impact seen from nutritional education, the study’s authors suggested this could reflect the focus of those behind education programs.

“Overall, it appears that nutrition education does not have an immediate and substantial effect on supermarket purchases, although it is notable that most interventions have been led by health professionals rather than by marketing and retail experts. It seems likely that application of commercial expertise and approaches would lead to bigger effects than those observed to date,”​ they wrote.

The authors concluded: “Our findings suggest that structural interventions are more powerful determinants of dietary behavior than those that rely on individual responsibility.”​

Source: American Journal of Clinical Nutrition​

doi: 10.3945/ajcn.2009.28742.

“Effects of price discounts and tailored nutrition education on supermarket purchases: a randomized controlled trial”​

Authors: Cliona Ni Mhurchu, Tony Blakely, Yannan Jiang, Helen C Eyles, and Anthony Rodgers