For more than 30 years, Dr. Robert C. Atkins challenged the conventional wisdom that fat is responsible for expanding Americans’ waistlines and spreading heart disease. Now his company is taking that case to Capitol Hill.

But followers of the low-carbohydrate diet guru, who died earlier this year, may have bitten off more than they can chew. The traditional food pyramid, which is being reviewed by the federal government, has its own powerful lobbies in Washington who are determined to protect their turf.

Lobbyists representing everything from sugar growers to frozen food makers and pasta manufacturers have contributed almost $2 million to Members of Congress this cycle and have deep roots on Capitol Hill. It’s no surprise that they would like to see the government make minimal — or no — changes to the pyramid.

“Scratching [the food pyramid] and starting over is not the best idea,” said Lisa Katic, spokeswoman for the Snack Food Association.

But Atkins Nutritionals Inc. and its backers disagree. “The food pyramid really needs to be reworked,” said Michael Jacobson, executive director of the Center for Science in the Public Interest. “It tries to do everything in one — point out the good and the bad. It can’t do that. There should be two.”

To further its position, Atkins has hired PodestaMattoon to help spread its message that carbohydrates and sugar are largely to blame for obesity in America.

“There has never been a voice in D.C. representing the 35 years of research that Dr. Atkins had under his belt,” said Atkins spokesman Richard Rothstein. “It’s like being at the Mad Hatter’s tea party — obesity is everywhere.”

Atkins scored an early victory last week at a Senate hearing on national dietary guidelines organized by Sen. Peter Fitzgerald (R-Ill.), who chairs the Commerce, Science and Transportation subcommittee on consumer affairs, foreign commerce and tourism.

Fitzgerald charged that the Agriculture Department has too many ties to food producers and therefore should not be in charge of setting dietary guidelines.

The chairman proposed giving sole custody of the important role to the Health and Human Services Department — which Fitzgerald believes would put the health of Americans above the interests of the food lobby — and cutting out the Agriculture Department.

“While it’s true that special interests influence virtually all policies coming out of Washington, in most cases the American public is cheated only in economic terms,” Fitzgerald said. “In the case of the dietary guidelines for Americans, however, there is the potential that citizens could be cheated out of advice that would protect their health and their lives.”

Fitzgerald added, “The USDA food guide pyramid probably has more to do with diabetes than Krispy Kremes. In fact, the pyramid’s advice to load up with six to 11 helpings of high-carbohydrate foods a day does more to promote the interests of grain and sugar producers than to promote the good health of ordinary Americans.”

To illustrate the cozy relationship that he claims exists between food producers and the Agriculture Department, Fitzgerald told reporters that the USDA and the traditional food lobby teamed up to cancel a similar hearing he was planning to hold within a subcommittee he chairs on the Agriculture Committee. Staffers for both the committee and the USDA, however, insisted otherwise.

But Fitzgerald forged ahead and said HHS should oversee the rewrite of the nutrition guidelines because the USDA has an inherent conflict of interest. Both departments currently oversee the process, with new guidelines due by January 2005.

Fitzgerald got an “amen” from both Atkins officials and government watchdog Jacobson, who also testified at the hearing.

Jacobson said the USDA “sees all farmers as constituents — be they spinach farmers, cattle ranchers or sugar growers,” regardless of their product’s nutritional merit.

But Atkins advocates face an uphill fight getting their message out to lawmakers, many of whom represent the same agriculture interests that support the traditional food pyramid. While Fitzgerald maintained that Senators have the issue on their radar screens, he had trouble getting his colleagues to show up for the hearing.

If one looks at recent donations to members of the Senate Agriculture Committee, food processors forked over almost $1 million; ranchers and pig farmers gave $350,000; dairy farmers contributed $277,000; and poultry and egg producers kicked in $252,000.

These numbers reflect donations from some of the biggest names in corporate America, such as Coca-Cola, Kellogg and H.J. Heinz, as well as various major trade groups including the Grocery Manufacturers, the American Meat Institute, the Snack Food Association, the American Sugarbeet Growers Association and many others.

While none of those interests testified at Fitzgerald’s hearing, all will participate in the debate, arguing that their foods and products are not to blame for America’s obesity and diabetes epidemic.

“For Americans to lead healthier lives and to reduce the risk of chronic disease, they need to find the right balance between what they eat and what they do,” the Grocery Manufacturers Association told the U.S. Dietary Guidelines Advisory Committee, which convened earlier this month.

“In some cases, this means consumers will need to moderate their food and beverage consumption to match their levels of physical activity.”

The Snack Food Association is also taking the stance that Americans need to up their exercise and that educators should promote physical education programs rather than have the government redraw the food pyramid, Katic said.

Katic added that Fitzgerald jumped the gun. “Congress should wait and see what the [advisory committee] does first before holding hearings,” she said.

Congress, of course, acted as the nutrition debate is front and center right now because of a confluence of events that Chandler Keys of the National Cattlemen’s Beef Association calls a “perfect storm.”

He noted that guidelines are being rethought at a time when obesity and diabetes are running rampant and Congress is reauthorizing school and low-income food programs.

While one would think Keys is happy to see Atkins — the high-protein champions — join the fray, he said the group does not endorse any particular diet.

But Keys said Atkins could become a powerful force. “They have a following out there,” he said. “They have a lot of believers. They’ve become a powerful commercial entity.”