By LIZ NEPORENT

When you get a bunch of nutrition eggheads in a room they sometimes fight about eggs. At April's Experimental Biology meeting in San Diego, they fought about sugar. Specifically, the type known as high fructose corn syrup, or HFCS for short.

The question before scientists at the symposium: Does the super-sweet food additive make a unique contribution to the obesity epidemic?  This is such a passionate topic in obesity research right now that professional debates such as this frequently turn sour.

The controversy was started by George Bray and Barry Popkin, two respected obesity researchers, who were immediately taken to task for a 2004 study suggesting that high fructose corn syrup has played a significant role in the global march of obesity. The study analyzed 30 years of data to show that the consumption of HFCS increased more than 1,000 percent in that time period, far exceeding changes in intake of any other food.

Many prominent researchers excoriated the science, pointing out that HFCS is chemically no different than any other type of sweetener; it's about 50 percent fructose and 50 percent sucrose, the same as table sugar, honey, concentrated fruit juice and agave syrup. They also pointed out that fructose consumption leveled off around the year 2000 but obesity rates have continued to rise.

At the conference, Bray was a presenter. He conceded those points but still insisted that fructose from any source is the most dangerous kind of sugar because the body metabolizes it differently.

Popkin, who sat in the audience, defends the idea as well.

"Fructose appears to have some powerful effects on the metabolism that are starting to look more potent than we heretofore understood," he says.

Among the metabolic dangers the anti-fructose scientists cite are an increase in abdominal fat, the type of fat associated with a greater risk of heart disease. Another presenter at the meeting, Dr. Robert Lustig, took the attack one step further, arguing that fructose is so highly addictive it's like alcohol without the buzz. He said a soda belly was not so far off from a beer belly.

These remarks didn't sit very well with the audience. Lustig and Bray endured a brutal grilling from their fellow scientists. There were arguments over whether or not breast milk is sweet and a gripe comparing fructose to cocaine. There was also a lot of grumbling about how little logic there is in blaming one food for disease when the Western diet is generally unhealthy.

"So many things have happened in our environment in the past fifty years, from a total increase in calories to a decrease in activity - it's absurd to pin the entire obesity problem on a single food such as fructose or even sugar consumption as a whole," said David Klerfeld, a national program leader in Human Nutrition for the USDA." Why aren't we focusing on ginormous portions rather than wasting time looking at single ingredients?"

At the end of the conference, no one walked away with a changed mind, and Popkin, for one, wasn't very happy. He claims one presenter who had just given a presentation about how sugar shouldn't be regulated or taxed admitted to him privately that he knew he was wrong.

"He deliberately left out some studies in order to be provocative," Popkin said.

And then there are accusations that everyone has too much skin in the game. Many of those who defend the use of fructose get research money from the Corn Refiners Association, while those on the other side of the fence have their professional reputations to preserve and books to sell.

All of this might seem like some arcane food fight if there weren't larger issues at stake. Backroom debates such as this shape the direction of future research and public policy funding, and as the topic spills over into public debate, it breeds confusion.

When consumers see there is no expert consensus it's difficult for them to make good nutritional decisions. "Then the quacks can come in and make a lot of outrageous claims that aren't true just to make money," Klerfeld says.

Whatever the right answer turns out to be, there was a consensus from all the scientists that we eat too much of everything and consume too many calories. And everyone agreed that the world is growing fatter by the minute. Currently nearly 70 percent of adult Americans are considered either overweight or obese.