This 12-week pilot study tested the design and methodology for a future randomised controlled trial of interventions to promote healthier food purchasing. Participants were customers of the participating supermarket (in Wellington) and were the main shoppers for their household. Each was randomised to 1 of 4 trial conditions comprising price discounts, nutritional education, a combination of both, or no intervention. Data on purchases were collected using the ‘Shop ’N Go’ electronic purchase system. The study found this method of electronic data collection was an effective way to measure the effects of the study interventions. Participant follow-up rate was 98%, and 85% of supermarket purchases were captured by the data collection system. However the authors noted difficulties recruiting sufficient numbers of Mäori, Pacific and low-income participants.
