Maine weighed in as the plumpest state in New England and the 27th most obese in the nation in the 2011 national “F as in Fat” study released Thursday.

The annual report found that Maine’s 26.5 percent adult obesity rate fell about halfway between Mississippi, ranked most obese with a 34.4 percent rate, and Colorado at 19.8 percent, the only state with a rate of less than 20 percent.

Other states in the Northeast ranked lower on the list than Maine: New Hampshire was 33rd most obese; New York, 41st; Rhode Island, 42nd; Vermont, 45th; Massachusetts, 48th; and Connecticut, 49th.

Last year, Maine’s obesity rate was 25.8 percent and it ranked 29th nationally.

The excess weight has health and financial impacts. More than 20 percent of the Medicare and Medicaid budgets go toward treating avoidable illnesses related to obesity and smoking.

The Trust for America’s Health and the Robert Wood Johnson Foundation, the report’s authors, called on lawmakers to refrain from cutting government programs aimed at fighting obesity.

“We can’t afford to ignore the impact obesity has on our health and corresponding health care spending,” Jeff Levi, executive director of the Trust for America’s Health, said in a statement accompanying the report.

In addition to ranking the states by percentage of obesity, the report also measured how fast obesity was growing in each state.

Maine was one of 16 states that saw an increase in obesity in the past year; 28 states reported increases in last year’s study.

Over the past 15 years, seven states have doubled their rates of obesity. Ten states had increases of more than 90 percent, and 22, including Maine, saw obesity rates increase by at least 80 percent. Fifteen years ago, Maine had an obesity rate of 14.3 percent and was ranked the 26th most obese state in the nation, the report said.

Correspondingly, diabetes rates have doubled in 10 states, including Maine, in the past 15 years. In 1995, Maine had a diabetes rate of 3.9 percent — now it is 8.4 percent. The hypertension rate in Maine rose from 21 percent to 28 percent over the same period, according to the report.

“Today, the state with the lowest adult obesity rate would have had the highest rate in 1995,” said Levi. “There was a clear tipping point in our national weight gain over the last 20 years.”

The study says a dozen states topped 30 percent obesity in 2010, most of them in the South. Alabama, West Virginia, Tennessee and Louisiana were close behind Mississippi. Just five years ago, in 2006, Mississippi was the only state above 30 percent.

Jim Marks of the Robert Wood Johnson Foundation said the numbers have skyrocketed over the past couple of decades because of the growth of portion sizes and the ready availability of unhealthy foods. Schools have ditched physical education programs and school lunches have gotten less healthy.

No state decreased its level of obesity, which is defined as a body mass index of 30 or more. The body mass index is a measurement based on a calculation using a person’s weight and height. A person who is 5 feet 5 inches and weighs 150 pounds would have a body mass index of 25, for example, but if that person weighed 180 pounds the BMI would be 30.

Although body mass index isn’t always the best indicator for someone with a lot of muscle, such as an athlete, it is considered the best way to measure the general population. The authors of the study say it allows them to measure large numbers of people because those surveyed can easily provide their height and weight.

As in previous years, the study showed that racial and ethnic minorities, along with those who have less education and make less money, have the highest obesity rates.

Adult obesity rates for African-Americans topped 40 percent in 15 states, while whites topped 30 percent in only four states. About one-third of adults who did not graduate from high school are obese; about one-fifth of those who graduated from college are considered obese.

Maine has been a leader in legislation to prevent obesity. The Legislature has approved measures requiring restaurants to provide dietary information about menu items and allowing school districts to measure students’ body mass index. Maine has higher nutritional standards for school food programs than the federal government.

It was also the first state to ban soda and candy from school vending machines and the first to ban advertising by food companies in schools.