Iron and Insulin Resistance in Overweight and Obese Humans

Determine the effects of reducing whole-body iron stores in overweight/obese subjects (via one-time blood donation) on adipose tissue iron content, factors regulating iron homeostasis and lipolytic rate in adipose tissue, as well as measures of adipose tissue and whole-body insulin resistance. After a screening visit to determine eligibility, subjects will undergo a battery of tests for the determination of primary outcome measures at baseline. They will then donate 1 unit (~500 mL) of blood (at a local blood donation center) and return for a follow-up testing 4 weeks after blood donation. During the 4-week period between study trials, subjects will be required to maintain a stable body mass and not alter their dietary or physical activity habits.