Impact of a Nudge-Based Food Environment Interventions in a Hospital Convenience Store on Staff’s Food Intake and Na/K

Abstract

Abstract Background A food environment intervention using nudge tactics was conducted in a hospital convenience store (CVS) in Tokyo to improve employees’ eating habits. The objective was to evaluate its effects on staff’s urinary sodium-to-potassium ratio (Na/K), food intake, eating attitude, and behavior.Methods Using a pre–post design; the intervention incorporated nudge tactics, more healthy options, easy-to-pick-up placement of food, and eye-catching information. We also used price incentives. Primary outcomes included change in Na/K and sodium and potassium excretion assessed using spot urine at health checkups. Secondary outcomes were the change in staff’s food intake, eating attitude, and behavior assessed using questionnaire surveys. All outcomes were statistically evaluated. Furthermore, we investigated how the intervention led to the outcomes using path analysis.Results A total of 140 participant (male: 52, female: 88) were statistically analyzed. Significant changes were observed in Na/K (3.16 to 2.98 in median, p = 0.015) and potassium excretion (43.4 to 45.2mmol/day in mean, p = 0.031). Sodium excretion showed no significant change. The intake of fruits and dairy products increased with improved self-efficacy. The most influential factor for lowering Na/K and increasing potassium excretion was information from the CVS; purchasing “balanced meals” to lower Na/K and salads to increase potassium excretion were second.Conclusions Food environment intervention using nudge tactics can improve staff’s food intake, lowering Na/K.Trial registration: Registration number: UMIN000049444 (UMIN-CTR).