the most common form of diabetes by far is type 2. previously known as adult-onset diabetes, it is now on the increase in children as well as adults. the condition can take years to develop and results from a combination of inadequate insulin production as well as increasing insulin resistance (rendering insulin less effective). As of 2005, 104.8 million Americans had either prediabetes or type 2 diabetes (more than 25 percent of the U.S. population) type 2 diabetes is fairly evenly split between men and women, according to the ADA