Oxytocin reduces post-stress sweet snack intake in women without attenuating salivary cortisol

Abstract

Intranasal oxytocin produces anorectic effects on snack intake in men when tested in the absence of deprivation-induced hunger, but its effects on food intake in women without eating disorders have not been reported. Oxytocin may reduce food intake by reducing stress eating, since it inhibits ACTH release. The present study adopted a double-blind, repeated measures and fully concealed crossover protocol in which 38 women self-administered 24 IU of oxytocin or placebo intranasally, ate lunch, and underwent two consecutive stress tests. Snack intake was assessed 15-20 minutes after lunch, via a sham taste test. Salivary cortisol was measured throughout the test period every 15 minutes. Oxytocin significantly reduced sweet fatty snack intake independently of any effect on salivary cortisol, which declined over time at a similar rate after either drug or placebo. Ratings of sweet taste were slightly reduced by oxytocin, but only in self-reported stress eaters. These results differ from previous studies with men that found an effect of oxytocin on postprandial cortisol levels. However, previous research assayed the less active form of plasma cortisol and did not control for protein intake, which can drive elevated cortisol. The finding that oxytocin reduces snack intake in females after acute stress has important implications for appetite regulation and its treatment in obese people and in those with eating disorders.

Can intranasal oxytocin reduce craving in automated addictive behaviours? A systematic review

“…This is partly consistent with studies with healthy volunteers, where intranasal oxytocin compared with placebo, is reported to be ineffective in modulating baseline, cue‐ or acute stress‐induced craving for food. However, this contrasts the reported effect of intranasal oxytocin in decreasing both energy intake after overnight fasting (Spetter et al, 2018; Thienel et al, 2016) and reward‐related eating (Burmester et al, 2018, 2019; Ott et al, 2013). The anorexigenic effects of oxytocin in humans are consistent with evidence from animal studies (Leslie et al, 2018).…”

Crosstalk between Schizophrenia and Metabolic Syndrome: The Role of Oxytocinergic Dysfunction

“…The implications of oxytocin in metabolic regulation are extended to exogenous oxytocin application in human studies. Contrary to several negative results [281,282], intranasal oxytocin treatment reduced the consumption of sweet foods [283,284], total caloric intake [285], reward-driven food intake [286], and food cravings [287] in humans, particularly in persons with obesity [288,289]. At the hormonal level, exogenous oxytocin treatment attenuated the peak excursion of plasma glucose and increased insulin secretion in response to the intravenous glucose tolerance test in healthy men [290].…”

The Effects of Oxytocin on Appetite Regulation, Food Intake and Metabolism in Humans

“…It should also be noted that while objective caloric consumption was reduced by oxytocin in some of these studies, subjective appetite as assessed by the visual analogue scale was unchanged under oxytocin treatment. While studies of oxytocin assessing hunger-driven eating show a reduction or no change in caloric intake, oxytocin consistently reduces hedonic food intake, assessed by palatable snack consumption, in satiated men and women across the weight spectrum [ 222 , 223 , 225 , 226 ]. These findings are in line with fMRI studies showing that in men with overweight and obesity, 24 IU of IN oxytocin reduced the blood oxygenation level-dependent (BOLD) signal in response to high-calorie food vs. non-food visual stimuli in the VTA [ 227 ], the origin of the mesolimbic dopaminergic reward system and a key hedonic brain region that drives efforts to obtain desired foods [ 32 , 228 ].…”