The Pew Research Center in Washington, D.C., says Americans believe their fellow Americans have become fat – but not themselves.

The Pew survey says most everyone considers obesity a serious national problem. But when they think about weight, they apparently use different scales for different people.

Nine-in-10 American adults surveyed by Pew said most of their fellow Americans are overweight. But just seven-in-10 say most people they personally know are overweight. And only fewer than four-in-10, or 39 percent, admit they are overweight.

The sliding assessments are drawn from a Pew Research Center telephone survey conducted Feb. 8-March 7 among a randomly selected, representative national sample of 2,250 adults. Officials did not provide a margin of error estimate.