Evaluation of a supermarket intervention to increase consumption of fruits and vegetables

Purpose. The purpose of this study was to evaluate whether a supermarket point-of-purchase intervention could increase shoppers' consumption of fruits and vegetables. Methods. Eight supermarkets in rural Iowa were randomized to receive either an 8-month intervention or no intervention. The intervention consisted of (1) one-page supermarket flyers that identified fruits and vegetables on sale, gave recipes and menu ideas for using sale foods, and gave a store coupon worth 50 cents toward the purchase of any fruit or vegetable; (2) store signage to identify fruits and vegetables featured on the flyer; and (3) consciousness raising activities such as food demonstrations and nutrition related signage. Evaluation war based on exit interviews and take-home surveys, competed by random samples of 120 shoppers from each store at baseline and approximately 1-year post randomization. Results. At follow-up, 42.9% of intervention store shoppers and 6.5% of control shoppers recalled seeing the intervention flyer. Thirty-six percent of intervention shoppers had used a 50-cent coupon and 18% had used a recipe. Approximately 70% of all shoppers had purchased fruits or vegetables on the day they were interviewed, which did not differ between intervention and control stores. Compared to change in control shoppers, there was a borderline statistically significant 8.4 percentage point increase (p < .07) in the percentage of intervention store shoppers in the action or maintenance stages of dietary change, but there was no corresponding increase in fruit and vegetable consumption. Discussion. Studies to test point-of-purchase interventions are difficult to design, implement, and evaluate. More powerful interventions are probably necessary to induce shoppers to purchase and consume more fruits and vegetables.