Towards healthier supermarkets: A national study of in-store food availability, prominence and promotions in New Zealand

Background/objectives: The retail environment is a key setting for potential public health interventions. This study assessed the healthiness of New Zealand supermarket food environments. Subject/methods: A sample of 204 (about 50% of national total) supermarkets across three chains was selected in 2016, half in the most deprived socioeconomic areas. Healthiness indicators related to food availability (ratio of cumulative linear shelf length for healthy versus unhealthy foods), prominence (proportion of 'junk food free' check-outs and end-of-aisle endcaps), and promotion (proportion of 'junk food free' promotions in flyers and in-store) were measured. Results: About 26.5% of supermarkets had at least 20% of check-outs junk-food-free and 17.2% had at least 60% of endcaps junk food free. On average 2/3 of food promotions in-store and of food promotions in flyers were junk food free. For every 1 m of shelf length for unhealthy foods, there was 42 cm of shelf length for healthy foods on average, with large variations between and within stores. In high and low prominence store areas there was on average 1 m of unhealthy foods for every 2 cm of healthy foods and 1 m of unhealthy foods for every 4 m of healthy foods, respectively. The shelf length ratio was significantly lower in the most compared to the least/medium deprived socioeconomic areas (p = 0.003). Conclusions: The large variations in healthiness indicators within and across chains present a great opportunity for retailers to improve the healthiness of supermarkets towards best practice.