By SUSAN SAULNY

c.2009 New York Times News Service

Marilyn Wann is an author and weight diversity speaker in Northern California who has a message for anyone making judgments about her health based on her large physique. “The only thing anyone can accurately diagnose by looking at a fat person is their own level of stereotype and prejudice about fat,” said Wann, a 43-year-old San Franciscan whose motto in life is also the title of her book: “Fat? So!”

Hers has been an oft-repeated message this summer and fall by members of the “fat pride” community, given that the nation is in the midst of a debate about health care. That debate has focused its attention on the growing population of overweight and obese Americans with unambiguous overtones: Fat people should lose weight, for the good of us all.

Heavier Americans are pushing back now with newfound vigor in the policy debate, lobbying legislators and trying to move public opinion to recognize their point of view: that thin does not equal fit, and that people can be healthy at any size.

Extra weight brings with it an increased risk of chronic disease, medical experts say, and heavier people tend to have medical costs that are substantially higher than their leaner counterparts. As a result, Congress is considering proposals in the effort to overhaul health care that would make it easier for employers to use financial rewards or penalties to promote healthy behavior by employees, like weight loss.

Other less-scientific arguments have also gained traction on blogs, chat shows and editorial pages, with the overweight cast as lazy or gluttonous liabilities and therefore not entitled to universal health coverage because of poor personal decision-making.

Either way, heavy people — characterized as over-consumers of health care or as those who should miss out on discounts because of their size — say they have been maligned.

“I thought, ‘Health reform? Yay!’ ” said Lynn McAfee, the director of medical advocacy for the Council on Size and Weight Discrimination, an advocacy group for heavy people. But McAfee said it was not long before her sentiment changed to the more sober, “Oh no, we’re being scapegoated again.”

Weight is an incendiary issue, experts said, and that may be why it had such staying power as a hot topic of conversation through the health care debate.

“All national health insurance systems are built on the idea that we’re all part of a community, we all get sick and die, so we’re going to take care of one another,” said James Morone, a professor of political science and urban studies at Brown University. “The best philosophical way to stop national health insurance is to say we’re not a community, it’s ‘us vs. them.”’

But what has been different about this issue, this year, is that “people are pushing back,” Morone said.