A 4 year study using MRI to look at knees showed the rate of knee degeneration/wear. The more weight loss, the slower the rate of knee destruction. Another study showed that combining weight loss with exercise with dietary modification improved exercise tolerance (walking) and improved weight loss. Finally, the proportion of obese patients with artificial knees requiring repeat replacement surgery has increased dramatically over the last 10 years. Obese is a modifiable risk factor for failure of Total Knee Replacement that should be addressed prior to knee replacement surgery.