WASHINGTON (AP) - A new poll finds that Americans blame too much cheap fast food for fueling the nation's fat epidemic, but they're split on how much the government should do to save them from themselves.

Most draw the line at policies that would try to force healthier eating by limiting food choices, according to the poll by The Associated Press-NORC Center for Public Affairs Research.

A third of people say the government should be deeply involved in finding ways to curb obesity, while a similar proportion want it to play little or no role. The rest are somewhere in the middle.

A third of U.S. children and teens, and two-thirds of adults, are either overweight or obese.

While three-quarters of Americans consider obesity a serious health problem, most of those surveyed said dealing with it is up to individuals.

That highlights the dilemma facing public health experts. Societal changes over recent decades have helped spur growing waistlines. Regular-sized food portions are larger, and a fast-food meal can be cheaper than healthier food.

In the current environment, it's difficult to exercise that personal responsibility, said Jeff Levi of the nonprofit Trust for America's Health.

"We need to create environments where the healthy choice becomes the easy choice, where it's possible for people to bear that responsibility," he said.

Require more physical activity in school? Provide nutritional guidelines to help people make better choices? Yes, 8 in 10 people surveyed support those steps. Make restaurants post calorie counts on their menus, as the Food and Drug Administration is poised to do? Some 70 percent think it's a good idea.

But nearly 6 in 10 people oppose taxes targeting unhealthy foods, known as soda taxes or fat taxes.

And when it comes to restricting what people can buy - like New York City's recent ban of supersized sodas in restaurants - three-quarters oppose it.

"The outlawing of sugary drinks, that's just silly," said Keith Donner, 52, of Miami, who prefers teaching schoolchildren to eat better and exercise.

More than half of women say the high cost of healthy food is a major driver of obesity, compared with just 37 percent of men. Women also are more likely to say that the food industry should bear a lot of responsibility for helping to find solutions.

Physical activity is an important factor too. About 7 in 10 people said it was easy to find sidewalks or paths for jogging, walking or bike-riding. But 63 percent found it difficult to run errands or get around without a car.

The AP-NORC Center survey was conducted Nov. 21 through Dec. 14. It involved landline and cellphone interviews with 1,011 adults nationwide and has a margin of sampling error of plus or minus 4.2 percentage points.

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Associated Press writers Lauran Neergaard, Jennifer Agiesta and Stacy A. Anderson and News Survey Specialist Dennis Junius contributed to this report.

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