Evaluating the Influence of Diet-induced Weight Loss on Fat (Adipose) Tissue's Insulin Sensitivity and Testosterone Synthesis in Women With Overweight or Obesity, Insulin Resistance, and Hyperandrogenemia

The investigators will measure the efficacy of a diet-induced weight loss intervention to reduce blood concentrations of the hormone's insulin and testosterone over the course of 2 months in women who have overweight or obesity and evidence of IR. Women meeting the eligibility criteria that have biochemical evidence or clinical manifestations of hyperandrogenemia (HA), or elevated blood androgens - testosterone or free testosterone - will be eligible for the dietary intervention arm of the study. A Mediterranean-based, calorie reduced, carbohydrate restricted diet will be employed to produce a 5% weight loss over the 8 weeks of the intervention. Participants will be provided with a full menu of meals and snacks for 4 of the 8 weeks in the study and will meet with a registered, licensed dietitian routinely for nutrition counseling and to ensure dietary compliance. Those in the dietary intervention will undergo 6 clinical visits at the Clinical and Translational Science's Unit whereas the control group (no dietary intervention or nutrition counseling) will undergo 2 clinical visits. Of the 6 study visits, 4 will include an adipose tissue biopsy and an oral glucose tolerance test. All visits will include DEXA measurement of body composition and collection of fasting blood samples. The control group's 2 study visits will occur at the start and end of the 8-week period and will include all study measurements (i.e., adipose tissue biopsies, oral glucose tolerance tests, DEXA scans, and fasting blood samples). Adipose tissue samples will be cultured and used to assess adipose-level insulin sensitivity. Area under the curve for insulin, glucose, and non-esterified fatty acids (NEFA) will be calculated from the samples collected during the oral glucose tolerance test. Additionally, the fasting HOMA-IR, Matsuda Index, QUICKI value, 2-hour blood glucose concentration, and NEFA suppression will be measured during the oral glucose tolerance test.