Half of all American adults are destined to develop diabetes or pre-diabetes by 2020 if they don't slim down, according to a dire new prediction that pegs the cost of their care at $3.35 billion by decade's end.

Sixty percent of the annual $500 billion burden of the obesity-driven obesity, epidemic, cost, diabetes epidemic would be borne by the U.S. government, according to "The United States of Diabetes," a provocative working paper produced by the Center for Health Reform & Modernization, part of the healthcare giant UnitedHealth Group Inc.