Grocery store intervention trials, including trials testing behavioral economics "nudges," may change food-purchasing behaviors and improve diet quality. This study aimed to design and evaluate a grocery store healthy checkout lane "nudge" intervention on sales of a targeted healthy item. We conducted a randomized controlled trial based on the behavioral economic concept of cognitive fatigue and the marketing concept of impulse buying. Six grocery stores from one North Carolina-based chain were randomized to the intervention (n = 3) or control (n = 3) condition. Researchers tested a 4-week healthy checkout lane intervention, in which intervention stores moved 6-ounce cans of peanuts to the cash registers. Cashiers were instructed to upsell the peanuts to all shoppers at checkout. While not a component of the intervention, the retailer decreased the price of the peanuts from $1.99 to $1.50 during the first 2 weeks of the intervention. Fidelity to the checkout display was high. Fidelity to the upsell was low. The main outcome measure was aggregated store-level sales of the promoted peanuts for 4 weeks before the intervention and during the 4-week intervention period. On average, sales increased by 10 units/week in intervention stores (5.83 vs. 15.83 units, p = .04) with no significant change in control stores (1.42 vs. 1.17 units, p = .64). The difference (10 vs. -0.25 units, p = .02) was likely due to displaying the peanuts at checkout combined with the price promotion. Larger randomized controlled trials should examine whether healthy checkout lane interventions are effective "nudges" for promoting purchases of healthier foods in grocery stores.
Keywords: behavior change; behavior change theory; community intervention; consumer health; health promotion; nutrition.