According to the latest data, West Virginia's adult obesity rate is tied with Mississippi for the highest in the country at 35.1%. Colorado has the lowest rate at 21.3 percent.
The annual report is produced by the Robert Wood Johnson Foundation and the Trust for America's Health.
In addition to being the most obese state, West Virginia is also the state with the highest percentage of people who do not exercise.
Among high schoolers, West Virginia ranks sixth, with 13 percent of those students obese.
The study finds across the country, every state has an obesity rate above 20 percent.
Officials at the foundation say these obesity rates put Americans at risk for a range of health problems and add a major burden to national healthcare costs. The report warns if obesity rates are not brought down, this generation of children may be the first in U.S. history to live sicker and die younger than their parents.
Its data shows West Virginia also has the second highest diabetes rate in the country at 13 percent.