BEN KLAUS—ISTOCKPHOTO
Top 10 Skinnier Spots: States Where Obesity Rates Are Lowest 1. Colorado: The obesity rate edged up to 18.9 percent last year, but that's still the lowest in the nation. Obesity is defined as a body mass index, or BMI, of more than 30, or 197 pounds on a 5-foot, 8-inch frame.
