Environmental Intervention in a University Canteen with Focus on Decision Guidance—Effects on Sale and Daily Consumption of Vegetables and Fruit

The purpose of the study was to evaluate whether an environmental intervention in a university canteen changes the sale and daily consumption of vegetables and fruit among canteen users. The intervention focused on decision guidance, including a positive incentive and nudging. In a pretest−posttest-design, daily sales data of pieces (pcs) of vegetable components and fruit, as well as the sale per main component (pcs/mc), were assessed. Here, 20 opening days were analyzed, each after the intervention (t1) and in the same period of the previous year (t0). Vegetable and fruit consumption were assessed in a controlled pretest−posttest design (3-day-dietary-record, t0 and t1). The intervention group (IG; n = 46) visited the canteen ≥ once/week, and the control group (CG; n = 49) < once/week. At t1, the sale of absolute vegetable components did not change (t0: 132.3 ± 49.7 pcs, p > 0.05), but more per main component were sold at t1 (t0: 0.54 ± 0.09, Δ: 0.09 ± 0.13 pcs/mc, p < 0.05). In addition, the sale of fruit (t0: 17.4 ± 11.6, Δ: 8.3 ± 10.8 pcs, p < 0.05; t0: 0.07 ± 0.03, Δ: 0.05 ± 0.07 pcs/mc, p < 0.001) increased after the intervention. The total consumption of vegetables (IG, t0: 260 ± 170 g/d, CG, t0: 220 ± 156 g/d; p > 0.05) and fruit (IG, t0: 191 ± 109 g/d; CG, t0: 186 ± 141 g/d; p > 0.05), however, did not change. To effectively change daily consumption, the intervention needs to be expanded.