If you have painful osteoarthritis (OA) of the knee, youre not alone. One of two people will develop knee OA at some point in their life, according to a study in the September 2008 issue of Arthritis and Rheumatism. If youre overweight, the lifetime risk is even greater: nearly two in three obese adults will develop knee OA. "Theres no question that weight loss is key to managing knee OA," says Santhosh A. Thomas, DO, MBA, staff physician with the Cleveland Clinic Center for Spine Health. Losing just 10 pounds relieves 40 pounds of pressure on your knees, and losing as little as 11 pounds can reduce joint pain and help prevent knee osteoarthritis. If you already have symptoms, losing 15 pounds can reduce your knee pain by half. You can benefit even if youre on the verge of knee-replacement surgery. Many patients have found that once they lose excess weight before knee replacement, they feel so much better that they call off the surgery. And even if they do undergo surgery, their post-op rehab is easier after weight loss.