Journal Article

Altering product placement to create a healthier layout in supermarkets: Outcomes on store sales, customer purchasing, and diet in a prospective matched controlled cluster study

Lord, Joanne, Crozier, Sarah, Baird, Janis, Cooper, Cyrus, Vogel, Christina, Penn-Newman, Daniel, Ball, Kylie, Moon, Graham

2021

Overview

Previous product placement trials in supermarkets are limited in scope and outcome data collected. This study assessed the effects on store-level sales, household-level purchasing, and dietary behaviours of a healthier supermarket layout. This is a prospective matched controlled cluster trial with 2 intervention components: (i) new fresh fruit and vegetable sections near store entrances (replacing smaller displays at the back) and frozen vegetables repositioned to the entrance aisle, plus (ii) the removal of confectionery from checkouts and aisle ends opposite. In this pilot study, the intervention was implemented for 6 months in 3 discount supermarkets in England. Three control stores were matched on store sales and customer profiles and neighbourhood deprivation. Women customers aged 18 to 45 years, with loyalty cards, were assigned to the intervention (n = 62) or control group (n = 88) of their primary store. The trial registration number is NCT03518151. Interrupted time series analysis showed that increases in store-level sales of fruits and vegetables were greater in intervention stores than predicted at 3 (1.71 standard deviations (SDs) (95% CI 0.45, 2.96), P = 0.01) and 6 months follow-up (2.42 SDs (0.22, 4.62), P = 0.03), equivalent to approximately 6,170 and approximately 9,820 extra portions per store, per week, respectively. The proportion of purchasing fruits and vegetables per week rose among intervention participants at 3 and 6 months compared to control participants (0.2% versus -3.0%, P = 0.22; 1.7% versus -3.5%, P = 0.05, respectively). Store sales of confectionery were lower in intervention stores than predicted at 3 (-1.05 SDs (-1.98, -0.12), P = 0.03) and 6 months (-1.37 SDs (-2.95, 0.22), P = 0.09), equivalent to approximately 1,359 and approximately 1,575 fewer portions per store, per week, respectively; no differences were observed for confectionery purchasing. Changes in dietary variables were predominantly in the expected direction for health benefit. Intervention implementation was not within control of the research team, and stores could not be randomised. It is a pilot study, and, therefore, not powered to detect an effect. Healthier supermarket layouts can improve the nutrition profile of store sales and likely improve household purchasing and dietary quality. Placing fruits and vegetables near store entrances should be considered alongside policies to limit prominent placement of unhealthy foods. ClinicalTrials.gov NCT03518151 (pre-results).

• Publisher: Public Library of Science,Public Library of Science (PLoS)
• Subject: Adolescent / Adult / Biology and Life Sciences / Candy / Choice Behavior / Commerce - economics / Computer and Information Sciences / Confectionery / Consumer behavior / Consumer Behavior - economics / Coronaviruses / COVID-19 / Design and construction / Diet / Diet, Healthy - economics / England / Female / Food - adverse effects / Food - economics / Food Preferences / Frozen Foods / Fruit / Fruits / Health aspects / Humans / Interrupted Time Series Analysis / Management / Medical research / Medicine and Health Sciences / Methods / Middle Aged / Nutritive Value / Obesity / Physical Sciences / Pilot Projects / Prospective Studies / Psychological aspects / Research and Analysis Methods / Social Sciences / Store design / Supermarkets / Time Factors / Vegetables / Young Adult