ESPE Yearbook of Paediatric Endocrinology

Obesity (Silver Spring) 2021 Jan;29(1):56–61.https://bit.ly/2Sz4SBz

Oxytocin was investigated in this small experimental study for its potential benefits on obesity. To test oxytocin for suppression of behavioural impulses, 10 men with overweight or obesity were subjected to a task assessing ability and strategy to suppress behavioural impulses. After receiving intranasal oxytocin, compared with placebo, participants showed increased reaction times in suppressing snacking in a satiety state.

Recent advances in nutrition suggest that the hypothalamic neuropeptide oxytocin acts as a critical central-nervous-system factor in mediating food intake and weight. Oxytocin is produced in the paraventricular and supraoptic nuclei of the hypothalamus, it decreases food intake in rodent, primate, and humans, and induces weight loss with minimal side effects. Consequently, oxytocin is under investigation as a potential new neurohormonal treatment for obesity. In humans, oxytocin reduces food intake without altering subjective appetite.

Cognitive control regulates impulses, habits, and decision-making, as well as its effect on controlling hedonic food intake. Individuals with obesity show impaired ability to exercise cognitive control on impulses and habits and more risky decision-making. Individuals with obesity show an increased responsiveness to food reward that renders them more susceptible to overeating, poor dietary choices, and ultimately weight gain. Intranasal administration of oxytocin reduces caloric intake but does not affect subjective appetite. The mechanism for this effect was unknown. Oxytocin affected hedonic eating (snacking in a satiety state) more than homeostatic food intake. These findings suggest that oxytocin exerts its effect on food intake through altering eating behaviour rather than by altering hunger signals.

These results open a new direction for investigation on cognitive control and its moderation in human obesity. Oxytocin becomes a new strategy in weight loss treatment as cognitive control can reduce the behavioural aspect of the urges to eat. Although the sample size of this pilot investigation is small, the overall pattern was consistent in 8/10 participants, suggesting that the reported finding reflects a robust and generalisable effect of oxytocin. The authors conclude that oxytocin triggers increased cognitive control over behaviour as the mechanism for anorexigenic effects of oxytocin in human obesity.