Understanding the Roles of Hormones in Adipocyte Remodeling Following Menopause

INCLUSION CRITERIA: * Healthy female * Ages 18-50 y * Planning to have either a laparoscopic bilateral oophorectomy or a laparoscopic unilateral oophorectomy (which would result in no remaining ovaries) * Are willing to drink heavy water (2H2O) over an 8-week period * Medically cleared for participation in the study by OB/GYN and Medical Investigator * Are willing to have blood and fat tissue stored for future use EXCLUSION CRITERIA: * Meet either of the following criteria: * Have all 3 of the major menopause-related symptoms \[hot flashes, mood swings, insomnia (trouble sleeping)\] * Have 2 of the major menopause-related symptom combinations \[hot flashes and mood swings, or hot flashes and insomnia (trouble sleeping)\] * Unstable weight in the last 3 months \[gain or loss \>7 lb (or 3.2 kg)\] * History of clinically diagnosed diabetes or a fasting blood glucose \>126 mg/dL * Chronic use of systemic glucocorticoids, antipsychotic/antidepressant medications, thiazolidinediones and other medications that cause clinically significant weight gain, weight loss or are known to make changes in fat cell number/size \* * Previous bariatric surgery (or other surgeries) for obesity or weight loss (\< 3 years ago) * Use of over the counter or prescription weight loss products * History of metabolic diseases (other than diabetes) * History of neurological disease * History of cardiovascular disease (or other chronic diseases) * Pregnant, planning to become pregnant, or breastfeeding * Use of hormone replacement therapy * Unwilling to discontinue any form or hormonal therapy (e.g., contraceptives including birth control pills, vaginal ring, injections, implant, or skin patch; hormonal supplements, etc.) upon enrollment (after the Screening Visit). * Inconsistent use of medications listed above will be evaluated and left up to the discretion of the Medical Investigator to evaluate safety.