Adult obesity rates increased in 16 states in the past year and did not decline in any state, according to an annual report from the Trust for America’s Health and the Robert Wood Johnson Foundation.

An average of 2008 through 2010 data showed that in 38 states, or more than two out of three, more than 25 percent of the population is obese. Only one, Colorado, has a rate of less than 20 percent.

According to the report, “F as in Fat: How Obesity Threatens America’s Future,” the District was the second-least obese of the jurisdictions studied, with an adult obesity rate of 21.7 percent, up from 21.5 percent the year before.

The District was slimmer than Maryland (27.1 percent) and Virginia (25.9 percent). Fifteen years ago, the District had an adult obesity rate of 12.8. Maryland’s rate was 15 percent, and Virginia’s was 14.2 percent.

This year, the report includes figures showing how the obesity epidemic has grown over the past two decades. Twenty years ago, no state had an obesity rate of more than 15 percent. Now, 38 states have rates of more than 25 percent. Obesity rates have grown fastest in Oklahoma, Alabama and Tennessee, and most slowly in the District, Colorado and Connecticut, according to the report.

“Today, the state with the lowest obesity rate would have had the highest rate in 1995,” said Jeff Levi, executive director of the Trust for America’s Health.

Adults with less education or who make less money, and racial and ethnic minority adults, continued to have the highest overall obesity rates. Nearly 33 percent of adults who did not from graduate high school are obese, compared with 21.5 percent of those who graduated from college or technical college.

More than 33 percent of adults who earned less than $15,000 per year were obese, compared with 24.6 percent of those who made at least $50,000 a year.

Adult obesity rates for blacks topped 30 percent in 42 states and the District.

In the District, adult obesity rates were 34.4 percent for blacks, 18.1 percent for Latinos and 9.3 percent for whites, virtually unchanged from the year before.

Researchers said the relatively low obesity rate in the District might be linked to growing numbers of white residents, who tend to have more education and earn more than blacks.

In Maryland and Virginia, the disparity between whites and blacks was less pronounced than in the District. In Maryland, the adult obesity rates were 36.3 percent for blacks, 27.4 percent for Latinos and 24.3 percent for whites. In Virginia, the rates were 37.2 percent for blacks, 25.1 percent for Latinos and 25.2 percent for whites.