Relationship between dietary intake and behaviors with oxytocin: a systematic review of studies in adults

Context: Oxytocin plays an important hormonal role in the regulation of feeding and energy intake. Objective: The aims of this review were to 1) determine the effects of dietary intake/behaviors on endogenous oxytocin and 2) examine the effect of exogenous oxytocin on dietary intake/behaviors. Data sources: Published studies up to December 2016 were identified through searches of 5 electronic databases. Data extraction: Eligible studies included those in adults that included a measure related to an individual’s diet and a measure of oxytocin and the relationship between the 2 outcomes. Results: Twenty-six studies (n = 912 participants; 77% female) were included. The most common dietary outcomes assessed were alcohol, caffeine, calcium, sodium, fat, and calorie intake. It was found that endogenous oxytocin (n = 13) in nonclinical samples did not change significantly (P > 0.05) through altered diet or behaviors (neutral effect); in contrast, significant (P < 0.05) differences (increases and decreases) were identified in clinical samples. Exogenous oxytocin studies (n = 13) found reduced indices of food intake (positive effect) in clinical and nonclinical samples. Conclusions: Overall, few studies included comprehensive investigation of dietary intakes through the use of validated assessment tools. Dietary intake and behaviors appear to have some influence on oxytocin, with more pronounced effects found with exogenously administered oxytocin.