For years, health experts have been warning that Americans are too fat, that we exercise too little and eat too much, that our health is in jeopardy. Some fat people beg to differ.Blogs written by fat people — and it’s fine to use the word, they say — have multiplied in recent months, filling a virtual soapbox known as the “fatosphere”, where bloggers calling for fat acceptance challenge just about everything conventional medical wisdom has to say about obesity.Smart, sassy and irreverent, bloggers with names like Big Fat Deal, FatChicksRule and Fatgrrl (“Now with 50 percent more fat!”) buck anti-obesity sentiment. They celebrate their full figures and call on readers to accept their bodies, quit dieting and get on with life.The message from the fatosphere is not just that big is beautiful. Many of the bloggers dismiss the “obesity epidemic” as hysteria. They argue that Americans are not that much larger than they used to be and that being fat in and of itself is not necessarily bad for you.And they reject a core belief that many Americans, including overweight ones, hold dear: That all a fat person needs to do to be thin is exercise more and eat less.“One of the first obstacles to fat acceptance is breaking down the question of whether being fat is a choice,” Kate Harding, founder of the blog Shapely Prose, said in an interview. “No fat acceptance advocate is saying you should sit around and wildly overeat. What we’re saying is that exercise and a balanced diet do not make everyone thin.”Harding, a 33-year-old yoga enthusiast from Chicago, promotes the idea of health at any size (she is a 16). She started Shapely Prose (kateharding.net) last April, after noticing that posts about fat in her personal blog hit a nerve. Since then, it has quickly become one of the most popular fat acceptance blogs, with an average of 3,710 page views per day, according to Sitemeter, a web statistics programme.People come in different shapes and sizes, bloggers like Harding say, and for those who come extra-large, dieting is futile. Many of the bloggers label their sites “no-diet zones”. (Don’t even mention weight-loss surgery.)“You relapse, and then you go on a diet again, and this time you’re going to do it, it’s really going to be it this time,” Marianne Kirby, a 30-year-old blogger from Orlando, Florida, who writes The Rotund (therotund.com), said in an interview. “And it still doesn’t work, not long-term — you end up heavier than before. And you say to yourself: Why did I fall for this again?’”The blogs have drawn their share of negative, even vicious comments. But for overweight readers, the messages are empowering — and liberating.“Girlfriend, let me tell you, I am finally coming to grips with myself,” one fan commented on Harding’s site. “I will always be fat. I accept that now.”