A new study shows Losing a large amount of weight slows the loss of knee cartilage in obese people. As obesity is a major risk factor for knee osteoarthritis, a degenerative joint disease that often leads to joint replacement surgery. This new study included just over 500 overweight and obese who either had mild to moderate osteoarthritis or risk factors for the disease. The study participants were randomly assigned to a control group that lost no weight, a group that lost a little weight, or a group that lost more than 10 percent of their body weight. Four years of follow-up showed significant weight loss protected against cartilage degeneration and that larger amounts of weight loss provided more protection, according to the study.