A total of 126 premenopausal women (42 lean, 42 obese with central obesity, 42 obese with peripheral obesity) will be recruited. Anthropometric measurements and body composition using DEXA will be collected. Overnight fasted subjects will be asked to give baseline blood samples before consuming a meal containing 6 mg 57Fe in the form of FeSO4. Subjects will return after 14 days and a blood sample will be collected for measurement of isotopic enrichment into red blood cells, serving as well as a baseline for the OGTT. Subjects will then be asked to ingest a solution of glucose (50g) containing 100 mg of iron in the form of sodium ferrous citrate (SFC), after which blood samples will be collected 2 hours post iron and glucose load. All three blood samples collected at baseline, 2 weeks post labeled iron load, and 2 hours post glucose/iron load will be analyzed for their levels of iron, glycaemia and inflammatory parameters.