Resting energy metabolism and sweet taste preference during the menstrual cycle in healthy women

Differences in blood concentration of sex hormones in the follicular (FP) and luteal (LP) phases may influence energy metabolism in women. We compared fasting energy metabolism and sweet taste preference on a representative day of the FP and LP in twenty healthy women (25 center dot 3 (SD 5 center dot 1) years, BMI: 22 center dot 2 (SD 2 center dot 2) kg/m(2)) with regular self-reported menses and without the use of hormonal contraceptives. From the self-reported duration of the three prior menstrual cycles, the predicted FP and LP visits were scheduled for days 5-12 and 20-25 after menses, respectively. The order of the FP and LP visits was randomly assigned. On each visit, RMR and RQ by indirect calorimetry, sweet taste preference by the Monell two-series forced-choice tracking procedure, serum fibroblast growth factor 21 by a commercial ELISA (FGF21, a liver-derived protein with action in energy balance, fuel oxidation and sugar preference) and dietary food intake by a 24-h dietary recall were determined. Serum progesterone and oestradiol concentrations displayed the expected differences between phases. RMR was lower in the FP v. LP (5042 (SD 460) v. 5197 (SD 490) kJ/d, respectively; P = 0 center dot 04; Cohen effect size, d(rm) = 0 center dot 33), while RQ showed borderline significant higher values (0 center dot 84 (SD 0 center dot 05) v. 0 center dot 81 (SD 0 center dot 05), respectively; P = 0 center dot 07; d(rm) = 0 center dot 62). Also, in the FP v. LP, sweet taste preference was lower (12 (SD 8) v. 16 (SD 9) %; P = 0 center dot 04; d(rm) = 0 center dot 47) concomitant with higher serum FGF21 concentration (294 (SD 164) v. 197 (SD 104) pg/ml; P < 0 center dot 01; d(rm) = 0 center dot 66). The menstrual cycle is associated with changes in energy expenditure, sweet taste preference and oxidative fuel partitioning.

Automated summary

Differences in blood concentration of sex hormones between the follicular and luteal phases can affect energy metabolism and sweet taste preference in women. This study found that women had lower resting metabolic rate, higher respiratory quotient, lower preference for sweet taste, and higher serum FGF21 concentration during the follicular phase compared to the luteal phase.