Effects of a Modest Energy Deficit on Reproductive Hormones Across the Menstrual Cycle in Contraceptive Users
University of Southern California
Summary
The purpose of the present study is to characterize the endocrine and metabolic responses to a modest, short-term energy deficiency (\~250 kcal/day) across the menstrual cycle in recreationally active women using different contraceptive methods (oral contraceptive, hormonal IUD, and non-hormonal IUD). This study will leverage daily urinary hormone metabolite tracking and comprehensive metabolic assessments, providing foundational data addressing an important and previously unexamined interaction between energy availability and hormonal regulation in contraceptive users.
Description
The purpose of the present study is to characterize the endocrine and metabolic responses to a modest, short-term energy deficiency (\~250 kcal/day) across the menstrual cycle in recreationally active women using different contraceptive methods. The investigators will be focusing on oral contraceptive users, hormonal IUD, and non-hormonal (i.e., copper IUD). Daily urinary hormone metabolite tracking and comprehensive metabolic assessments (i.e., resting metabolic rate, body composition via DXA, exercise logs, and energy intake) will be used to provide foundational data addressing an important…
Eligibility
- Age range
- 18–35 years
- Sex
- Female
- Healthy volunteers
- No
Inclusion Criteria: * Female, aged 18-35 years * Recreationally active (engaging in structured exercise between 8-15 hours per week) * BMI of 18.5-29.9 as a BMI below or above these cut points results in highly varied menstrual cycle lengths17 * Not currently experiencing an eating disorder or disordered eating, or having a diagnosed eating disorder in the last 3 years * Non-pregnant or planning to become pregnant * Medically free from chronic diseases * Currently using one of the following contraceptive methods for ≥3 months: Monophasic oral contraceptive * Hormonal intrauterine device (H-…
Interventions
- BehavioralEnergy Deficiency of approximately ~250 kcal/day
Following an initial baseline menstrual cycle, participants will be subjected to at least two weeks of a \~250 kcal/day energy deficit monitored through daily diet tracking.
Location
- University of Southern California Health Sciences Campus Center for Health ProfessionsLos Angeles, California