This is a pilot study to determine the optimal length of dietary intervention for subsequent studies. Normal women will be studied during the early follicular phase of two consecutive menstrual cycles. The women will be admitted to the GCRC for 3 days of a controlled diet, which will consist of either 3 meals plus a snack daily, or the same number of daily weight-maintenance calories given as a single evening meal. On the third day of each diet, each subject will undergo 24 hours of q15 minute frequent blood sampling for glucose and insulin. Each women will undergo a 20 minute insulin tolerance test on the following morning before discharge. The subjects will be readmitted in the following early follicular phase for the same protocol on the oppsite diet. Daily 24 hour urine collections will be made each day of each admission to evaluate stress by urinary cortisol and catecholamine levels. Six to eight normal women will be studied in this pilot to determine if three days of a controlled diet are sufficient to induce a change in insulin levels. Subsequently, the appropriate study length will be utilized in future studies of hyperandrogenic and diabetic women along with additional analyses.