According to results from part of Gallup's Healthways Well-Being Index, which is based on interviews conducted daily across the U.S., over 20% of Americans in all states are obese. Obesity rates were calculated based on respondents' reported height and weight, which was then used to calculate their Body Mass Index (BMI) scores. Respondents with BMI's of 30 and above were considered to be obese. The tables (right) show the ten states with the lowest and ten states with the highest obesity rates from January to June 2011. As the tables indicate, Colorado was the state with the lowest obesity rate of 20.1% and West Virginia was the state with the highest obesity rate at 34.3%. The national obesity rate from January to June 2011 was 26.3%. While the national obesity rate was about the same from January to June 2010 at 2.6.6%, the survey found that obesity rates are generally rising in states where they are already highest and declining in states where they are already lowest. The map (right) illustrates the regional nature of obesity, with Southern and Midwestern states genearlly having obesity rates in the "higher range" and Northeastern and Western states having obesity rates in the "lower range" to "midrange."