Heart disease is the leading cause of death in the United States, while diabetes is No. 6. And obesity contributes to both of them.

Mississippi is the unhealthiest state of all. Nearly a quarter of the population is obese, which is the highest percentage of all the states, and there are 235.8 deaths from heart disease per 1,000 people, the fourth worst in the nation. In addition, 6.2 percent of the population has diabetes.

Even the so-called "healthiest" states aren't all that healthy. None of the states has an obesity rate in the single digits. Colorado comes closest with 13.8 percent of residents deemed obese, as defined by having a body mass index of 30 or above.

The 10 least healthy states:

1. Mississippi 2. West Virginia 3. Tennessee 4. Michigan 5. Louisiana 6. Texas 7. Kentucky 8. Illinois 9. Missouri 10. Arkansas

The top three healthiest states:

1. Montana 2. Hawaii 3. Minnesota

What makes Mississippi less healthy than Montana? Researchers suspect diet.