Overview

The purpose of this study is to learn more about reproductive hormones and if they change in response to 5-days eating an individualized, standardized diet at two levels: energy balance and low energy intake.

Eligibility

Inclusion Criteria:

• Female
• Age 18-30
• Body mass index between 18.5-24.9 OR 30-45
• Have regular menstrual cycles between 18-40 days over the past 6 months
• Weight stable (not gained or lost 5kg) in the past 3 months

Exclusion Criteria:

• Using hormonal birth control currently or within the past three months
• Polycystic ovary syndrome (current or past diagnosis)
• Pregnant, lactating, planning to become pregnant in next 6 months
• Engaging in regular intentional aerobic exercise
• Significant medical issues (e.g.,cardiovascular disease or diabetes)