The suit by Jody Gorran, filed Wednesday in Palm Beach County Circuit Court, seeks $15,000.
Gorran, 53, said Thursday he started the diet in May 2001 because his weight had risen from 140 to 148 pounds. In two months, he said, his cholesterol rose from a normal 146 to an unhealthy 230, and by October 2003, he needed heart angioplasty to clear his arteries.
"I came very close to dying, and this is from a diet I thought was marvelous," said Gorran.
Atkins Nutritionals said in a statement that it stands by the science that has "repeatedly reaffirmed the safety and health benefits of the Atkins Nutritional Approach."
The company questioned the motivation of a Washington-based advocacy group that helped Gorran with the suit. The group, the Physicians Committee for Responsible Medicine, promotes a vegan diet banning meat, fish, dairy and egg products.
"We should not let the real issue, providing people with a scientifically validated nutritional choice in the face of a worldwide obesity and type 2 diabetes epidemic, be manipulated by this extremist animal rights vegan group," Atkins Nutritionals said in a statement.
For years, doctors and nutritionists have debated the Atkins diet, which advocates meat, eggs and cheese, frowns on bread, rice and fruit, and allows up to two-thirds of calories from fat, more than double the usual recommendation.
The diet doctor, who died last year at 72 after falling on an icy sidewalk in New York, argued that carbohydrates generate too much insulin, which makes people hungrier and encourages them to put on fat. His books, including the best-selling "Dr. Atkins' New Diet Revolution," have sold 15 million copies and attracted millions of followers.
The advocacy group said Gorran's suit is the first to recently question the merits of the Atkins diet. In 1979, a New York jury rejected an elderly, overweight woman's lawsuit claiming that the Atkins Diet caused her heart disease.
Gorran, who owns a company that makes solar panels for swimming pools, said he believes Atkins products should warn of a risk for developing health problems when eating meat and other foods that are endorsed by the diet and are high in saturated fat.
"For 2½ years, I extolled the virtues of this diet to anyone who listened because I was losing weight and I felt great. But when I started, I had no idea I was making a deal with the devil for trying to keep a 32-inch waistline," he said.
By Jill Barton