Rheumatoid arthritis is an autoimmune disease that can cause painful inflammation in the fingers and other joints. Richard Rudisill/iStockphoto.com hide caption

itoggle caption Richard Rudisill/iStockphoto.com

New York City food carts would also be affected by Mayor Michael Bloomberg's proposal to ban sugary drinks 16 oz. and larger. Andrew Burton/Getty Images hide caption

itoggle caption Andrew Burton/Getty Images

Karlton Hill, 15, was diagnosed with diabetes when he was 12. He works hard to manage the disease: He jogs and does pushups every day; he takes metformin is very careful about what he eats. Leslie Capo/LSU Health Sciences Center hide caption

itoggle caption Leslie Capo/LSU Health Sciences Center

It's not clear if diet soft drinks are the healthiest choice. ASSOCIATED PRESS hide caption

itoggle caption ASSOCIATED PRESS

Studies show that friends and family gain weight — and lose weight — together. Sean Locke/iStockphoto.com hide caption

itoggle caption Sean Locke/iStockphoto.com

The FDA hasn't approved a new weight-loss drug since 1999. In the meantime, Americans' waistlines have continued to grow. M. Spencer Green/AP hide caption

itoggle caption M. Spencer Green/AP