A man is suing the estate of diet guru Robert Atkins for $28,000, claiming the eating plan caused his cholesterol levels to soar dangerous levels.
Atkins dieters are urged to eat a high amount of red meat
Jody Gorran, 53, took up the low-carbohydrate, high-protein Atkins diet for two years in a bid to lose weight.
He says it raised his cholesterol so much that he had to undergo a medical procedure to unclog blocked arteries.
Mr Gorran's case is being backed by Physicians Committee for Responsible Medicine, who advocate veganism.
He says he wants Atkins products to warn of the potential dangers of raised cholesterol levels.
The diet encourages people to eat low amounts of carbohydrates and higher amounts of fat and protein.
The New York Times newspaper reported that Mr Gorran, of Delray Beach, Florida turned to the diet in 2001 when his weight increased to 10.5 stones (67kg).
But after two months, his cholesterol rose from a healthy level of 146 milligrams per decilitre to 230, considered potentially dangerous.
He said he continued to adhere to the diet because the book warned one in three dieters could see a rise.
Mr Gorran says the book tells these people to eat lean proteins such skinless chicken breast and fish but to return to the normal version of the diet if they prefer it.
In October 2003, after three episodes of chest pain, doctors found that a major artery was almost completely blocked.
He needed an angioplasty and a stent inserted to unblock the artery.
Mr Gorran says that, before he started the diet, tests showed that his arteries were clear.
'Make people think'
Two months after coming off the Atkins diet, where his favourite foods were cheese every day and cheesecake three times a week, his cholesterol dropped to 146.
He said: "I contend there ought to be a warning on this diet.
"I'm seeking an injunction to prevent them from selling their products, books, or having their website without a warning, because they know one-third of the people on the diet will have what Atkins referred to as 'less favourable cholesterol.' "
He added: "The whole thing is based on getting the word out. Even if the suit never gets anywhere, we'll be out there and people will start to think."
A statement from Atkins Nutritionals and the estate of Dr. Atkins said it stood by "the science that has repeatedly reaffirmed the safety and health benefits of Atkins."
It added that the Physicians Committee for Responsible Nutrition was "a well-known vegan and animal rights group, has a long history of initiating these kinds of scare tactics that are designed to convince the American public to stop eating animal protein of any sort."
Mr. Gorran said he had linked up with the group because it was "familiar with publicity.''
The American Heart Association said it would not comment on the lawsuit, but a spokesman said, "Eating large amounts of high-fat foods for a sustained period raises the risk of coronary heart disease, diabetes, stroke and several types of cancer."
Professor Benjamin Zipursky, of Fordham University's School of Law in New York, said the lawsuit had legal shortcomings which he felt would prevent it succeeding.
Professor Zipursky added: "It really reads as if it were done by someone who is doing it for reasons of publicity rather than private gain.''
Dr Amanda Wynne, of the British Nutrition Foundation, would not comment on the individual case.
But she said: "Diets that are high in saturated fats are linked with increases in blood cholesterol."