Experts at the Centers for Disease Control and Prevention (CDC) were surprised by the findings of a diabetes study. The study showed that diabetes rates increased only slightly from an estimated 8.2% of adults in 1988-1994 to 8.6% in 1999-2000, despite a sharp increase in obesity. CDC health officials had anticipated a larger increase because obesity has been rising rapidly. During the 1990s, obesity rose by 61%. As of 2000, 19.8% of US adults were obese, according to the CDC. The officials warned, however, that because diabetes is a slow-developing disease, diabetes rates could increase sharply over the next few years.