Nutrition education delivered through grocery retailer improves DASH diet adherence

People who received personalized nutrition education in a series of sessions conducted at their regular grocery store significantly improved their adherence to the Dietary Approaches to Stop Hypertension (DASH) diet, in a study presented at the American College of Cardiology's 71st Annual Scientific Session. The diet, which emphasizes vegetables, fruits and whole grains while limiting foods that are high in saturated fat, sugar and sodium, has been shown to lower blood pressure and LDL, or "bad" cholesterol.

The Supermarket and Web-based Intervention Targeting Nutrition (SuperWIN) Trial, a partnership between academic researchers and the grocery retailer Kroger, is the first to deliver a nutritional intervention in each participant's home grocery store guided by their personal food purchasing data. Comparing participants' eating habits at the start of the study and three months later, in-store nutrition education sessions significantly increased DASH adherence scores by 4.7 points on top of an enhanced standard of care group, which increased DASH scores by a baseline amount of 5.8 points alone. Combining in-store nutrition education sessions with online tools and training increased DASH scores by an additional 3.8 points compared to the nutrition education sessions without the online resources.

"Small changes in diet actually have enormous health impacts, especially if sustained over time. SuperWIN may help address the gap between current dietary guidelines and poor public adherence to these recommendations," said Dylan L. Steen, MD, adjunct associate professor of medicine at the University of Cincinnati College of Medicine and the study's lead author. "It is a small step, but SuperWIN really highlights the potential of research partnerships beyond the pharmaceutical, biotech and medical device industries to design and test new health care approaches and reach patients in their communities. This study, for example, really demonstrates the efficacy of a grocery store-based dietary intervention."

The academic research team led the study design and analysis, while Kroger provided in-store dietitians, clinic space, and each participant's grocery purchasing data collected by a newly issued Kroger loyalty card. A total of 247 participants were recruited through a primary care network. After completing an initial screening and baseline data collection process, participants were randomized into three different study groups.

The control group received enhanced medical nutrition therapy in a single in-store session with a dietitian but no further nutrition education. One intervention group received six additional one-on-one in-store nutrition education sessions focused on following the DASH dietary pattern. The other intervention group also received a total of seven one-on-one in-store nutrition education sessions, plus training on tools for online shopping, free home grocery delivery, identification of healthier foods and meal planning. Each session in both intervention groups was guided by updated, individualized purchasing data that was provided to the dietitian and the participant for review.

"These interventions really allowed individualization of the DASH diet to each participant," Steen said. "The dietitians taught participants how to eat better right within the aisles of their home grocery store. The magic is that they not only are registered dietitians, but their expertise extends to the store's inventory of products and the brands and products preferred by customers. When provided the dietary and purchasing information about each participant, they were able to use these findings to better incorporate healthy changes into each participant's lifestyle and budget."

The dietitians also used information about participants' tastes, cooking experience and food allergies to make tailored recommendations.

Going forward, Steen said that rigorous validation of retail-based interventions will be critical to drive innovation and adoption. New services can also be designed to better integrate into care provided by primary care physicians. The researchers plan to further analyze the data for additional insights into participants' experiences, food literacy, purchases and other health markers.