Story Highlights Hawaii and Colorado are the only two states with obesity rate below 20%

Obesity rate exceeds 30.0% in 18 states

Fourteen states have seen significant increases in obesity since 2008

WASHINGTON, D.C. -- At 18.5%, Hawaii has the lowest adult obesity rate in the U.S., closely followed by Colorado at 19.8%. They are the only two states in which the obesity rate is below 20%. West Virginia has the highest adult obesity rate, at 37.0%. In addition to West Virginia, at least one in three adults are obese in Mississippi, Delaware, Arkansas and Oklahoma.

Percentage of Obese Adults, by State Obese % States with lowest obesity percentage Hawaii 18.5 Colorado 19.8 Massachusetts 23.6 New Mexico 23.7 Nevada 23.9 California 23.9 Montana 24.1 New Hampshire 24.3 Utah 24.5 New Jersey 24.7 States with highest obesity percentage West Virginia 37.0 Mississippi 35.5 Delaware 33.8 Arkansas 33.5 Oklahoma 33.5 Ohio 31.6 Maine 31.5 Michigan 31.5 Kentucky 31.4 South Carolina 31.4 Gallup-Healthways Well-Being Index, 2015

These data, from daily interviews conducted January through December 2015 as part of the Gallup-Healthways Well-Being Index, are based on U.S. adults' self-reports of their height and weight, which are then used to calculate Body Mass Index (BMI) scores. Americans who have a BMI of 30 or higher are classified as obese.

The national obesity rate reached a new high of 28.0% in 2015, up significantly from 25.5% in 2008, when Gallup and Healthways began tracking obesity. Fourteen states had statistically significant increases in their obesity rates from 2008 to 2015, while no state registered a statistically significant decline. Maine, West Virginia, Idaho and Oklahoma experienced the sharpest upticks in obesity.

States With Statistically Significant Increases in Obesity, 2008 to 2015 2008 % 2015 % Increase pct. pts. Maine 24.9 31.5 6.6 West Virginia 30.5 37.0 6.5 Idaho 24.0 29.7 5.7 Oklahoma 28.0 33.5 5.5 Iowa 26.4 31.3 4.9 Michigan 26.7 31.5 4.8 Ohio 27.6 31.6 4.0 South Carolina 27.6 31.4 3.8 North Carolina 26.7 30.4 3.7 Texas 27.1 30.7 3.6 Georgia 26.0 28.8 2.8 Washington 24.5 27.1 2.6 Florida 24.2 26.5 2.3 Pennsylvania 27.2 29.2 2.0 Gallup-Healthways Well-Being Index

Obesity Remains Highest in the South, Lowest in the West

Of the 18 states with obesity rates of at least 30.0%, all but one are located in the South or Midwest. Meanwhile, all 11 states with obesity rates below 25.0% are located in the Northeast or West.

Since 2008, the obesity rate for the Midwest has increased by 3.2 percentage points, more than any other region. The South followed closely behind, with a 2.9-point increase. The Northeast and West have seen smaller, but still statistically significant, increases of 2.0 and 1.8 points, respectively.

Regional Changes in Adult Obesity Rates, 2008 to 2015 % Obese 2008 % 2015 % Increase pct. pts. Midwest 26.8 30.0 +3.2 South 27.0 29.9 +2.9 Northeast 24.2 26.2 +2.0 West 22.8 24.6 +1.8 Gallup-Healthways Well-Being Index

As Obesity Rates Rise, So Do Healthcare Costs

Given that obesity is associated with illnesses such as heart disease, diabetes, stroke, osteoarthritis and some forms of cancer, the medical costs for an obese person amounted to $1,429 more per year than for a person of a normal weight, according to research conducted in 2008 by RTI International and the Centers for Disease Control and Prevention. After adjusting for inflation, the annual medical costs for 2015 are $1,573 more for a person who is obese than for a person of a normal weight.

Gallup calculated the incremental cost of healthcare per year for each state by multiplying the estimated number of obese people in the state's population by the annual incremental $1,573 cost of obesity per person.

In the five most obese states, the annual incremental cost of obesity per 100,000 residents averages $54 million. By contrast, the average cost is $34 million in the five least obese states. In other words, per capita medical costs attributable to obesity are about 1.6 times higher in the five states with the highest obesity rates than in the states with the five lowest rates. Additional annual medical costs attributable to obesity for each state appear at the end of the article.

States' Annual Incremental 2015 Healthcare Costs Attributable to Obesity Population (estimate) Obese % Annual healthcare cost per 100k adults Annual healthcare cost all adults States with highest percentage of obese adults West Virginia 1,452,598 37.0 $58,273,467 $846,479,005 Mississippi 2,163,049 35.5 $55,914,797 $1,209,464,207 Delaware 697,965 33.8 $53,223,481 $371,481,197 Arkansas 2,215,461 33.5 $52,743,928 $1,168,521,191 Oklahoma 2,767,117 33.5 $52,647,884 $1,456,828,340 States with lowest percentage of obese adults Hawaii 1,049,465 18.5 $29,067,060 $305,048,588 Colorado 4,019,462 19.8 $31,109,252 $1,250,424,550 Massachusetts 5,144,065 23.6 $37,087,771 $1,907,818,922 New Mexico 1,596,641 23.7 $37,245,304 $594,673,741 Nevada 2,095,527 23.9 $37,539,385 $786,648,014 Gallup-Healthways Well-Being Index, 2015

Implications

As the adult obesity rate continues to rise both nationally and within many states, preventable healthcare costs will also rise. If states can lower their obesity rates, even modestly, they can achieve significant cost savings and improve their residents' well-being.

"There's no better time than now to comprehensively look at what drives people to make sustained changes in their lives, as the costs of obesity are staggering, both financially and personally," says Sean Slovenski, president, Population Health Services at Healthways. "We know from both science and experience that to be effective, the weight-loss journey needs to be personalized, easy to implement and supported."

But reducing obesity rates is no easy task. Gallup previously found that Americans are twice as likely to want to lose weight as to say they are seriously trying to do so. Most of the burden for reducing obesity falls on individuals and how motivated they are to consistently make healthier choices. This motivation is often difficult to find and maintain, but there are proven population health interventions that are effective in supporting sustained weight loss.

"We can reverse our nation's growing obesity epidemic," says Dan Buettner, National Geographic Fellow and founder of Blue Zones Project, a community well-being improvement initiative of Healthways and its community partners. "The key is creating an environment that makes the healthy choice not only easy but at times unavoidable -- so that people will eat less, eat better, move more and connect socially. Communities that have the courage to implement simple, evidence-based designs and policies that support lasting change, such as Los Angeles Beach cities, are seeing a measurable reduction in obesity and healthcare costs, and an increase in well-being."

In the long run, interventions designed to prevent and reduce obesity at both the individual and community levels can potentially lead to substantial cost savings for families, employers and states.

Survey Methods

Results are based on telephone interviews conducted Jan. 2-Dec. 30, 2015, as a part of the Gallup-Healthways Well-Being Index, with a random sample of 177,281 adults, aged 18 and older, living in all 50 U.S. states and the District of Columbia. For results based on the total sample of national adults, the margin of sampling error for the Well-Being Index score is ±0.1 point at the 95% confidence level. The margin of sampling error for most states is about ±0.6 points, although this increases to about ±1.6 points for the smallest population states such as North Dakota, Wyoming, Hawaii and Delaware. All reported margins of sampling error include computed design effects for weighting.

Each sample of national adults includes a minimum quota of 60% cellphone respondents and 40% landline respondents, with additional minimum quotas by time zone within region. Landline and cellular telephone numbers are selected using random-digit-dial methods.

Learn more about how the Gallup-Healthways Well-Being Index works.