References
hedonic sensations, bloating, nausea, digestive sensations, Hedonic sensations, fat overload
BLIND
Experimental procedure and design. A sham-controlled, parallel, randomized, blind study was performed, measuring the responses to meal ingestion on four consecutive days. On day 1, a comfort meal was administered. On day 2, an offensive meal (the same meal with a masked fat overload and colour additive) was administered. On day 3, the original comfort meal with the colour additive was administered, to detect the effect of aversive conditioning by previous exposure to the offending meal. On day 4, a cognitive intervention was performed (disclosing the aversive conditioning paradigm in the test group, but not in the control group) and the comfort meal was subsequently retested. Each study day digestive sensations were measured by means of scales during the pre-ingestion period, during consumption, and following ingestion of the probe meal. The arrows at the bottom of the image represent the time points at which the sensations (outcomes) were measured.Hedonic sensations. The comfort meal on day 1 was associated with a gratifying postprandial experience, which was significantly reduced after aversive conditioning on day 3 mimicking the response to the offending meal on day 2; this effect reverted by the cognitive intervention on day 4, thereby restoring the hedonic value of the comfort meal. Aversive conditioning (i.e., the difference in the AUC on day 3 minus day 1) was equivalent between groups. The effect of the cognitive intervention (i.e., the difference in the AUC on day 4 minus day 3) was different than that of the sham intervention in the control group. Values represent mean ± SE.Homeostatic sensations. Aversive conditioning was associated with an increase in satiety, fullness/bloating, and mild abdominal discomfort. No differences between groups were detected for the effects of aversive conditioning (i.e., the difference in the AUC on day 3 minus day 1) or the cognitive intervention (i.e., the difference in the AUC on Day 4 minus Day 3) for satiety, bloating, discomfort, or nausea. Values represent mean ± SE.Meal valence during the ingestion phase. The administration of the comfort meal was carried out in a stepwise manner, divided into four equal servings; meal wanting was measured before each serving and at the end of ingestion; meal liking was measured after each serving. On day 1, participants enjoyed the comfort meal, but meal wanting and liking were significantly reduced after aversive conditioning on day 3; this effect reverted by the cognitive intervention on day 4, thereby restoring the reward value of the comfort meal. The effect of aversive conditioning (i.e., the difference in the AUC on day 3 minus day 1) was equivalent between groups. The effect of the cognitive intervention (i.e., the difference in the AUC curve on day 4 minus day 3) was significantly different from that of the sham intervention in the control group. Values represent mean ± SE.Generalised linear mixed model for hedonic sensations.* Generalised linear mixed model for homeostatic sensations.* Generalised linear mixed model for meal valence.*** 