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Changes in hunger and fullness in relation to gut peptides before and after 8 weeks of alternate day fasting

Hoddy, Kristin K., Gibbons, Catherine, Kroeger, Cynthia M., Trepanowski, John F., Barnosky, Adrienne, Bhutani, Surabhi, Gabel, Kelsey, Finlayson, Graham, Varady, Krista A.
Clinical nutrition 2016 v.35 pp. 1380-1385
compliance, diet, digestive system, energy intake, fasting, ghrelin, hunger, insulin, lean body mass, leptin, resting metabolic rate, visceral fat, weight loss
Alternate day fasting (ADF; 25% energy intake “fast day”, alternated with an ad libitum intake “feed day”) is effective for weight loss. Whether or not ADF modulates hunger, fullness and gut peptides in a way that enhances dietary compliance and weight loss, remains unknown. Accordingly, this study examined the effect of ADF on postprandial appetite ratings and gut peptides.Obese subjects (n = 59) participated in an 8-week ADF protocol where food was provided on the fast day.Body weight decreased (P < 0.0001) by 3.9 ± 0.6 kg after 8 weeks of diet. Reductions (P < 0.05) in fat mass (−2.2 ± 0.2 kg), fat free mass (−1.4 ± 0.2 kg), visceral fat mass (−0.1 ± 0.1 kg), and resting metabolic rate (RMR; −104 ± 28 kcal/day) were also observed. Fasting leptin and insulin decreased (P < 0.05), while AUC ghrelin levels increased (P < 0.05). Despite these metabolic changes, there was no increase in subjective hunger by the end of the study. Furthermore, fullness and PYY increased (P < 0.05). Fat free mass and RMR were not related to hunger or ghrelin at any time point.These findings suggest that the absence of a compensatory increase in hunger in conjunction with an increase in sensations of fullness may contribute to the weight loss efficacy of an 8-week ADF regimen.