Can health information and Price incentives promote whole-grain bread choices? A real purchase experiment in China

Despite growing evidence linking whole grains to improved health outcomes and food system sustainability, consumption remains critically low in China, underscoring an urgent need for effective interventions. This study investigated the effects of information intervention and price subsidy on promoting whole-grain bread choices among Chinese consumers, using a controlled quasi-experiment in a real supermarket in urban Beijing. Three conditions—information intervention, price-subsidy intervention, and control—were implemented in separate time slots over the course of eight days. The information intervention featured the recommended whole grain intake levels from the 2022 Chinese Dietary Guidelines, displayed next to whole-grain bread products. The price-subsidy intervention provided a post-purchase cash rebate, reducing the price of high whole-grain content bread products to match the lowest-priced bread available in the experiment. A total of 364 participants' choice records from shopping receipts were collected, consisting of 132 in the control group, 126 in the information intervention group, and 106 in the price-subsidy intervention group. Compared to those in the control group, participants in the price-subsidy intervention group had significantly increased choices of high whole-grain content bread (OR = 4.67, 95% CI 2.61–8.38), whereas the information intervention showed no effect on whole-grain bread choices (OR = 0.95, 95% CI 0.58–1.56). The effects remained robust after adjusting for individual socio-demographic characteristics and shopping day. Our findings suggest that, in China, price subsidies may be more effective in promoting whole-grain consumption compared with providing health information in complex retail environments.