The influence of sex and self-control on the efficacy of nudges in lowering the energy content of food during a fast food order

An experiment aimed at reducing calorie content of a food order was performed by introducing interventions at the fast food ordering screen on a tablet computer. Modifications included a virtual order assistant, a color-coded system and highlighting low-calorie choices. Participants of the study were 401 university students. Before starting an order, participants were asked to indicate their calorie goal. Our results show that the order assistant is the only intervention that leads to significantly fewer calories in the fast food order. The effect is due to women ordering fewer high-calorie dishes. Men, in contrast, are unresponsive to changes in the choice context regarding calories ordered. Results indicate that the level of self-control moderates the impact of the feature highlighting choices so that higher levels of self-control lead to lower calorie intake for both sexes. This research highlights the importance of gender and self-control for designing choice environments aimed at decreasing calorie intake.