Abstract
The psychobiological effects of the menstrual cycle on both self reported food intake and subjective experiences of appetite were assessed in a series of studies. A significant premenstrual increase in both sugar intake (determined by semi weighed method) and carbohydrate preference was observed. In addition, although not significant, total calorific intake peaked premenstually. Subjective appetite rating scores also significantly altered during the cycle, with maximum appetite noted in the luteal stage. Altered perception of hunger and satiety were observed premenstrually. Significant correlations between food intake and subjective experiences of appetite were observed, with percentage protein intake being related to the degree of satiation experienced, and food cravings to absolute and percentage fat intake. The role of serotonin (involved in the inhibition of eating and the control of macronutrient intake) was investigated to identify its putative mediation of eating control during the menstrual cycle. Initially, the metabolism of its precursor, tryptophan was clarified during the menstrual cycle, and led to the development of a salivary assay to measure tryptophan and a wide range of its metabolites. Correlational studies did not identify a role for serotonin in affecting either the inhibition of eating nor macronutrient choice during the menstrual cycle. However, a premenstrual association between the subjective overconsumption of food and increased serotonin production (relative to kynurenine metabolites) was identified. The role of mood in affecting eating control was also investigated. No effects were noted on self-reported food intake. However, mood did significantly modulate subjective experiences of eating with positive moods in the follicular and luteal stages predictive of the degree of satiety; whereas negative moods (specifically depression and hostility) were predictive of low satiation premenstrually. Comments regarding methodological issues, and areas for further research are highlighted.