H1) Palatability ratings
SESSION
Results of the palatability ratings are reported in Table Palatability ratings results.f = 0.18p = 0.02f = 0.32p < 0.001f = 0.31p < 0.001Palatability ratings at pre- and post-intervention. Trimmed means of palatability ratings are represented for the control and experimental interventions. Individual data points, means (bold circle), distributions’ density (violin), medians, first and third quartiles (horizontal bars), and the 1.5 inter-quartiles range (whiskers) are represented. *p < 0.05, **p < 0.01, ***p < 0.001.For the triple interaction (H1) Intervention x Session x Drink Type, the homoscedasticity assumption was not respected (Levene’s Test: F(7, 680) = 5.8, p < 0.001). Hence, a non-parametrical ANOVA was computed. It revealed a significant triple interaction, driven by a different training effect between healthy and unhealthy items’ palatability ratings (Statistic(1, 169.89) = 16.2, p < 0.001).The triple interaction was split into two follow-up Intervention x Session interactions for the unhealthy (H1a) and healthy (H1b) drink items separately. Both of these double interactions had their homoscedasticity assumption respected (H1a: F(3, 340) = 2.3, p = 0.08; H1b: F(3, 340) = 2.4, p = 0.07). Confirming our hypotheses for both the unhealthy (H1a) and healthy (H1b) items, the interactions reach significance and with above-threshold effect sizes (i.e., differences of pre-post deltas > 5%). The interaction was driven by a larger reduction of palatability ratings in the experimental than control intervention for the unhealthy items (delta of pre-post deltas = 8.6, F(1, 170) = 16, p < 0.001), and by a larger increase in the experimental than control intervention for the healthy drinks (delta of pre-post deltas = 6.8, F(1, 170) = 5.4, p = 0.02).