Oxytocin Reduces Reward-Driven Food Intake in Humans

Abstract

Experiments in animals suggest that the neuropeptide oxytocin acts as an anorexigenic signal in the central nervous control of food intake. In humans, however, research has almost exclusively focused on the involvement of oxytocin in the regulation of social behavior. We investigated the effect of intranasal oxytocin on ingestion and metabolic function in healthy men. Food intake in the fasted state was examined 45 min after neuropeptide administration, followed by the assessment of olfaction and reward-driven snack intake in the absence of hunger. Energy expenditure was registered by indirect calorimetry, and blood was repeatedly sampled to determine concentrations of blood glucose and hormones. Oxytocin markedly reduced snack consumption, restraining, in particular, the intake of chocolate cookies by 25%. Oxytocin, moreover, attenuated basal and postprandial levels of adrenocorticotropic hormone and cortisol and curbed the meal-related rise in plasma glucose. Energy expenditure and hunger-driven food intake as well as olfactory function were not affected. Our results indicate that oxytocin, beyond its role in social bonding, regulates nonhomeostatic, reward-related energy intake, hypothalamic-pituitary-adrenal axis activity, and the glucoregulatory response to food intake in humans. These effects can be assumed to converge with the psychosocial function of oxytocin and imply possible applications in the treatment of metabolic disorders.

Oxytocin Nasal Spray in the Treatment of Binge Eating Disorder and Obesity: A Pilot, Randomized, Double-Blind Trial

“…It has been observed that oxytocin reduced the intake of palatable foods, but was not able to modify food intake in the fasted state [10]. Accordingly, the lack of efficacy in reducing food intake observed in our study may be due to the energy-restricted diet received by participants.…”

“…Preclinical studies indicate that oxytocin administration decreases food consumption and body weight in obese and lean animals [5] but the few clinical studies conducted to date have produced conflicting results [9][10][11][12].…”

“…This route of administration allows oxytocin to penetrate into the central nervous system, likely through olfactory epithelial intercellular spaces [13]. In one study, the administration of this formulation (24 IU) to individuals of normal weight reduced the consumption of palatable food but not hunger-driven eating [10]. In another study, the administration of oxytocin nasal spray (24 IU) to obese patients, four times a day, approximately 20 min before meals and sleep for 8 weeks effectively reduced body weight [11].…”

Oxytocin in survivors of childhood-onset craniopharyngioma

“…Oxytocin has also been linked to energy homeostasis mechanisms in animals, where it acts as a strong inhibitor of food intake and affects energy expenditure and glucose homeostasis [27][28][29][30][31]. Oxytocin has also been shown to play an important role in metabolism and energy balance in humans [32,33], such as reducing caloric intake with a preferential effect on fat intake [11] and reward-driven food intake in humans [34]. These findings are in line with our finding that reduced levels of delta oxytocin correlate with a high BMI in CP patients.…”

Central and peripheral control of food intake

“…Moreover, animal studies and pilot experiments in humans have indicated that oxytocin might have a role in the regulation of eating behavior and metabolism in normal weight as well as with diet-induced obesity. Oxytocin administration in animals and humans inhibits food intake, increases energy expenditure, and reduces glucose levels (Morton et al 2012;Ott et al 2013;Lawson et al 2015). Interestingly, there are experiments, which suggest that the metabolic eff ects of oxytocin may be even enhanced in diet-induced obese in comparison to control weight (Th ienel et al 2016) with absent or minimal side eff ects.…”