Osteoarthritis affects over 32 million adults in this country. A new study suggests that gaining even a small amount of weight significantly worsens arthritis of the knees. In the study, presented at the International Congress on Obesity, Australian researchers reviewed the data for over 250,000 patients. They found that an increase of just 11 pounds increased the chance of needing a knee replacement 34 percent for women and 25 percent for men. Pain and other arthritis symptoms became more severe as they gained weight, and their x-ray signs of arthritis worsened. Doing what you can to maintain a healthy weight appears to be a great way to avoid joint replacements down the road.