The use of hypnosis can generate hallucinatory phenomena, which ranged from vivid/auditory imagery to fully developed "hallucinations" in selected people. The aim of this pilot trial was investigating the acute effects of a hypnosis-induced hallucinated breakfast (HB) compared to those of a real breakfast (RB) on subjective appetite and appetite-regulating hormones in highly hypnotizable individuals. Eight healthy post-menopausal women were recruited to consume two meals: the HB and the RB in a randomized crossover design. Participants underwent appetite sensations measurements (before meal and each 30-min until 270-min) and blood sample collection (at 0, 20, 60, 90, 180-min). A 3-day food-record was filled after each meal. The adjusted repeated measures ANCOVA did not show any meal×time interactions on subjective appetite postprandially. As expected, significantly higher glucose (p < 0.001), insulin (p < 0.001), and lower free fatty acid (p < 0.001) concentrations were found after the RB, but not following HB. Furthermore, RB significantly increased postprandial levels of glucagon-like-peptide-1 and peptide-YY at 20, 60, 90 and 180-min, whereas acylated-ghrelin and leptin levels did not differ. Postprandial neuropeptide-Y and orexin-A values significantly increased at different time-points after RB, but not following HB, while α-melanocyte-stimulating hormone levels enhanced after HB only. Energy intakes were significantly lower after HB on the test-day only (HB = 1146.6 ± 343.8 vs RB = 1634.7 ± 274.2 kcal/d; p = 0.003). Appetite sensation might be modulated by fully developed meal "hallucination" induced by hypnosis, likely affecting brain-peptides implicated in the appetite regulation. However, further studies are needed to verify these results obtained in a highly selected group of individuals. NCT03934580.
Keywords: Appetite; Hypnosis; Obesity; Orexin, Neuropeptide-Y.