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An annual report put out by two public health groups shows that America is getting fatter. Adult obesity rates have increased in 16 states in the past year, with 12 states now reporting at least 30% of their populations as obese.

Only one state in the nation, Colorado, long one of the slimmest, has an adult obesity rate below 20% — but at 19.8%, just barely. Mississippi ignominiously leads the fat pack with a 34.4% rate of obesity. No states showed a decrease since the previous year.

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The swollen statistics come from the fifth annual “F as in Fat” report, put out by Trust for America’s Health and the Robert Wood Johnson Foundation. This year was the first that the researchers also looked at data spanning the previous two decades, in addition to doing their year-to-year update, and the long-term comparisons show much starker jumps in obesity. Twenty years ago, no state had an adult obesity rate above 15%, and 15 years ago Mississippi was the fattest state, with a 19.4% obesity rate — notably lower that than of the least obese state today. When the overweight population is counted with the obese, current rates by state consistently top 60%.

“It’s not unlike with individuals,” says Jeffrey Levi, executive director for Trust for America’s Health. “You add a pound or two every year and after 10 or 20 years, it becomes a significant thing, and that’s sort of what the country has done.”

The highest obesity rates are in the South, large swaths of which are poor and rural, and where fried foods are eaten in abundance. Following Mississippi, the most obese states are Alabama, West Virginia, Tennessee and Louisiana. It’s not until No. 10 on the list, Michigan, that a state above the Mason-Dixon Line appears. The least obese states continue to be in the West and Northeast.

In a foreword to the report, former Surgeon General David Satcher presents a concrete number of Americans, 190 million, who are overweight or obese. And he outlines the most important facets of the “epidemic” as he sees them: the associated health problems that are on the rise, from Type 2 diabetes to cancer; bloated health-care costs; and “food deserts” where largely poor communities have little access to healthy food. As in previous years, the report showed that lower-income groups and minorities tend to have more widespread obesity.

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Type 2 diabetes rates in 11 states and the District of Columbia have risen in the past year, the report found, and all but four states have seen increases in rates of high blood pressure in recent years. Today, every state has hypertension rates over 20%, with nine over 30%. Twenty years ago, 37 states had hypertension rates over 20%.

Satcher and Levi both warn against viewing the problem as a series of personal failures. “We need a combination of opportunities that will make healthy choices easier, on the food front and the activity front,” Levi says. “There’s always going to be an element of personal responsibility, but even when people are motivated, if you live in a neighborhood where the only food that’s available is high-density fast food, it’s going to be very hard to carry through on that personal commitment.”

Levi points to the First Lady’s Let’s Move campaign as a model to follow. “You need to be addressing those environmental and those policy factors, but at the same time, you need to be motivating the country,” he says. “This isn’t going to be solved by Washington waving a magic wand. This is going to be solved community by community.”

The one piece of silver-lining news is that the number of states reporting increases in obesity in 2011 was down to 16, from 28 the previous year. The group of states maintaining their weight has been gradually increasing, Levi says, but “even if we’re leveling off, we’re leveling off at an unacceptably high level.”

Katy Steinmetz is a reporter at TIME. Find her on Twitter at @KatySteinmetz. You can also continue the discussion on TIME’s Facebook page and on Twitter at @TIME.