The best treatment for improving the symptoms of METS is weight loss. In previous studies, it has been demonstrated that whey protein (WP) supplementation increased weight loss and especially fat-mass loss in obese, insulin resistant women when compared to carbohydrates. We now propose to compare WP to another protein source in patients with the METS during weight loss. In addition, we will use a special preparation called partially hydrolyzed whey protein, which may have specific properties that increase fat mass loss.