Hormone Fluctuations, Dietary Intake, and Daily Activity in Premenopausal Women: An 8-Week Observational Study

Female reproductive hormonal fluctuations may be influenced by lifestyle behaviors such as diet, physical activity (PA), and sleep. However, little is known about these interactions over time or how they may differ between naturally menstruating (NM) and hormonal contraceptive (HC) women. This 8-wk observational study examined relationships between hormone levels and dietary intake, PA, exercise, and sleep quality, and explored differences by menstrual cycle phase and contraceptive status.

Sixteen premenopausal women (NM = 9, HC = 7; age: 21.2 ± 2.8) completed weekly serum blood draws, 24-h dietary recalls, Simple PA Questionnaire, and Pittsburgh Sleep Quality Questionnaire. Body composition was measured at baseline.

In HC participants, leptin was positively associated with dietary fat (r = 0.348, P = 0.019). In NM participants, estradiol positively predicted daily calorie intake (β = 0.134, P = 0.019), added sugar intake (β = 0.0028, P = 0.0013), and was positively associated with total fat intake (r = 0.427, P = 0.003). Progesterone positively predicted added sugar intake (β = 0.12, P = 0.0024). Luteinizing hormone was negatively associated with calories (r = -0.327, P = 0.029), carbohydrate (r = -0.406, P = 0.006), and added sugar (r = -0.380, P = 0.010). Sex hormone binding globulin was positively associated with added sugar (r = 0.427, P = 0.003). In NM participants, leptin was positively associated with sedentary time (β = 0.072, P = 0.048). No other significant associations existed between hormones or menstrual cycle phase and PA, exercise, or sleep.

Dietary intake was more strongly linked to hormone levels in NM than HC participants. Self-reported activity and sleep quality appeared consistent across the study, suggesting limited behavior fluctuations across the menstrual cycle.