Effect of the menstrual cycle on energy and nutrient intake.

Midfollicular and midluteal dietary intakes of 18 women were evaluated between four and six ovulatory menstrual cycles. Phase lengths were established by basal body temperatures and urinary luteinizing hormone excretion. Midfollicular and midluteal diet records were collected 6-8 d after menstrual onset and 6-8 d after ovulation, respectively. Significant increases in energy [0.66 MJ (159 kcal), P = 0.003], protein (6.1 g, P = 0.02), carbohydrate (15.3 g, P = 0.04), and fat (8.6 g, P = 0.002) intakes were observed in midluteal phase when compared with midfollicular phase. Intakes of vitamin D, riboflavin, potassium, phosphorus, and magnesium also were significantly higher during midluteal phase (P < 0.05). These results support the regulation of food intake by menstrual cycle hormones and suggest that it is essential to consider phase of menstrual cycle in studies of nutrient intake performed in premenopausal women.