The Great Weight Debate: Is It OK to Be Fat? Four fiery panelists debate whether you can be fat and healthy.

Feb. 23, 2010 -- From plus-size to big boned, pleasantly plump to succulently shapely, and Rubenesque to curvy, no matter how you dress it up, for decades, the world "fat" has been associated with laziness, filth and inactivity. It's become a pop culture punch line.

Recent headlines show just how mainstream the issue of obesity has become.

Last week, film director Kevin Smith was ejected from a Southwest airlines flight after being deemed too large for his seat. First lady Michelle Obama has recently launched a campaign to fight childhood obesity. Even former president Bill Clinton links his continual heart problems to poor eating habits as a child.

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The message in all of this is that fat is bad. And with a $50 billion industry of weight loss drugs, bestselling books, and workout programs, there appears to be no end in sight.

But has it all gone too far? Linda Bacon, a professor of nutrition whose book, "Healthy at Every Size," has become a kind of bible for the so-called fat acceptance movement, thinks it has.

"That's an extraordinary amount of money that we are all putting out right now to support an industry that doesn't have our best interests in mind," Bacon said. ""I think that we've reached the point where these ideas about weight are now so strongly part of our cultural landscape that we don't even challenge them, we don't even recognize that they are assumptions. We just accept them."

Bacon says her research shows that we shouldn't be focusing so much on fat.

"There are about 40 studies that have been conducted that have looked at longevity and weight," she said, "and almost all of them are showing that people that are in the category that we call overweight are actually living longer lives than people that are in the category that we deem normal and advisable."

On the other hand, the federal government says that two thirds of adults in America are overweight, 72 million are clinically obese. The Centers for Disease Control and Prevention estimated that in 2008, 9.1 percent of all health care spending in the U.S. -- $147 billion – was spent on obesity-related medical care, much of that paid for by taxpayers.

So who's right? Has America become a dangerously supersized nation or is it all an unhealthy obsession with being thin?

To help answer the question, "Nightline" brought together four outspoken people for a "Nightline Face-Off: Is It OK to Be Fat?" The debate is part of the "Face-Off" series, which has debated controversial issues including atheism, porn, Satan and adultery.

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Fat Acceptance Movement 'Takes Us Backwards'

The debate took place at the Cooper Union's historic Great Hall in downtown Manhattan. On one side of the issue were Kim Bensen and MeMe Roth. Benson, a former obese woman spent a lifetime yo-yo dieting, and finally dropped the weight after tipping the scales at 347 pounds.

"I lost over 200 pounds and have kept it off for over 7 years," she said. "I'm really excited to be here today to talk about the topic."

Bensen was partnered up with Meme Roth, one of the most outspoken members of the ant-obesity movement and the head of National Action Against Obesity (NAAO). Roth does not believe that a person can be fat and healthy. She also believes that obesity bears a major financial burden to taxpayers.

"The big problem with this pro-fat acceptance movement is it takes us backwards," said Roth, "and it makes us pretend like we're debating whether obesity is bad, but obesity is bad."

On the other side of the debate were Marianne Kirby and Crystal Renn. Kirby, who proudly identifies herself as fat, is a leader of the Fat Acceptance Movement. In her book, "Lessons from the Fat-o-Sphere," she argues that fat can be beautiful and healthy.

Kirby believes that fat men and women should not be ashamed and should accept their bodies, no matter what they are, without judgment.

"[MeMe] says a lot of inflammatory things that I think are pretty damaging to people," said Kirby prior to the debate, "but she's not a monster, she's not crazy. She's just a person. I'm not here to throw cupcakes at her."

Panelist: 'I Couldn't' Breath' When I Was Obese

Kirby was joined by Crystal Renn, the world's highest-paid plus-size model, and author of "Hungry: A Young Model's Story of Appetite, Ambition and the Ultimate Embrace of Curves." When she started modeling, she was a size zero, and she dieted her way to an eating disorder and a slew of health problems.

"I actually suffered from an eating disorder, anorexia, for three years, and it nearly took my life," said Renn. "And today, I can speak about health at any size because I really lived it through life experience."

As the audience gathered inside the Great Hall, the panelists made last minute preparations and met each other for the first time. After introductions, the panelists sat down and went through their opening arguments.

Kirby kicked off the debate. In America, one in three people is obese, but she believes that the health risks associated with obesity are exaggerated and it is possible to be overweight and healthy.

"I think that we look at health from an incredibly narrow standpoint," said Kirby. "I think that if you are eating healthfully if you are taking care of your own personal health… if you are taking care of those things, that's a completely divorced issue from weight."

Bensen, who struggled with her weight for most of her life, strongly disagreed. "I think it's very scary to be saying that you don't have health risks when you're overweight. I know from personal experience. I couldn't breathe when I slept at night."

"That does not mean that my situation affects my health in X, Y, Z," said Kirby. "So the blanket statement that there are all of these nasty consequences for being fat is kind of naive thing for us as a s society to believe."

Dieting Debate: 'I'm This Size Because I Dieted'

Soon, the debate moved into mental health. In America, about 10 million women and one million men suffer from eating disorders. With issues like low self esteem on the table, the panelists were then asked if Americans, particularly children, where too fixated on the issue of size versus health.

"I think the most important thing that we can give to a child is a love for the body," said Roth, "and having cake and ice cream at someone's birthday party isn't why Americans [are] fat. It's acting like every day is somebody's birthday party is why America is fat.

"Food is a pleasurable thing," said Renn. "It can be a pleasurable thing in moderation. I absolutely believe there is nothing wrong with celebrating a birthday with something pleasurable such as food."

But Roth wasn't finished. "We've gotten ourselves to the point where we're behaviorally and neurochemically dependent upon food," she said. "[It's] fine to have birthday party food at a birthday party. But we say, 'Oh, you had a good day, here's cake, you had a bad here's cake, you got a promotion, here's cake.'"

"But what about when you start to go the other way and you say, 'Oh my God, food let's be scared now.' That's such a bad thing," said Renn, "I think that's also planting the anorexic seed possibly from the beginning in children's minds."

Kirby then opened up about her personal battle with dieting and her eventual acceptance of her weight. "I mean I started out as a kind of chubby kid and increased through all of these behaviors...I'm this size because I dieted for 20 years. And when you stop --"

"Well dieting doesn't get you to that size," said Benson.

"It does actually," Kirby responded. "So when you go through the cycle of weight gain and reloss and gain and loss and gain and loss, you wind up this size."

"I know I did! I was bigger than you. A lot," said Bensen, "But you're not answering my question."

"It's not about giving up," said Kirby. "I gave up dieting because it was a loser game for me. It made me fatter. It made me incredibly unhealthy. It made me full of self loathing... I have permanently screwed up my metabolism because I dieted from age 7 to the age of 27...When I stopped dieting my body settled, [it] stopped changing. And my health improved."

Some studies have shown that women who yo-yo diet may actually gain more weight over time than those who don't. Another study found that just 5 percent of dieters keep the weight off after five years. Roth thinks that's because people don't really understand what it means to eat healthy.

"I can't eat more than 1,300 calories if I'm not gonna exercise," said Roth. "That's not a lot of food. So I run for four miles a day and I'm eating somewhere close to 1,800 calories a day."

Renn Goes After MeMe's Personal Eating Habits

Renn seemed perplexed. "Excuse me a second," she said. "Sorry, I just want to understand what you said. You're saying that you run four miles a day and eat only 1,800 calories... That's really interesting and that's just about 300 calories off where I was about four years ago when I was really sick and had hair falling out of my head."

"You're 5 foot 9," said Roth.

"You're right. I'm not saying you have anorexia," said Renn. "I definitely believe there is something going on cause you're quite passionate and I think a little fat phobic."

"There's a lot of studies looking at staying at a lower end of BMI [body mass index] perhaps giving us longevity and healthier longevity," said Roth.

Renn then delved deeper into her own personal battle with anorexia. "So when I was eating 1,000 calories a day and lost my menstrual cycle for three years and might not be able to have children that I think says something. [That's] way too little."

The Economics of Obesity

The panelists also tackled the economics of obesity. People say at what point does ones right to be fat impinge on someone's airline seat, ambulance trip, or hospital bed?

"If you require two of something you should pay for two of something," said Roth. "No one's ever sold me a seat at a discounted rate because I don't take up the entire seat. I'm not sure that I am buying into discrimination for obesity. I'm looking at the numbers and the discrimination may be on the few of us who are staying healthy, eating properly and subsidizing an obese culture."

Kirby was incensed. "No! MeMe Roth just said that thin people are discriminated against," she said. "That's amazing."

"They certainly are," Roth shot back.

As the debate came to an end, panelists lingered to answer audience questions, many of them aimed at MeMe Roth.

"It's hard as hell," she told one overweight audience member. "It is so hard to make yourself exercise every day. It is so hard to say no to the plethora of delectable things that you could eat at all times, but damn it people, it is wrong to be sick, it is wrong to make yourself sick, and it is wrong to make every other citizen of this country pay the price for it."

Despite the wide range of arguments and viewpoints that emerged during the "Face-Off," there were several points of agreement. The panelists all agreed that quality foods, fruits and vegetables should be available for everyone. They also agreed that no one should be stigmatized based on their size.

"The fact that people don't do it is not the same as can't do it," said Roth. "She's done it," she said referring to Benson. "There are many people who do it. Now I am not saying it's easy. I'm not saying that more than five percent do it. But I'm not saying that it's impossible."

"My body and my health don't look like everybody else's body and their health," said Kirby. "Everyone is an individual. Everyone has ... their own challenges, when it comes to their health, however that's defined. And I think that it's incredibly damaging to judge someone ... and their health levels, based solely on this one factor. It's ridiculous."

CLICK HERE to watch the full "Face-Off" debate