Even so, such cases are raising concerns within the industry.

At a recent food and beverage conference attended by more than 100 lawyers, Madeleine M. McDonough, a lawyer at Shook, Hardy & Bacon who is co-chairwoman of the agribusiness and food safety practice, warned in a session on fraud litigation that it was imperative for companies to comply with federal regulation. “Otherwise, we are dead in the water,” she said, according to two lawyers present, including J. Price Coleman, who is working with Mr. Barrett’s group.

If the lawsuits prove successful, the liability could be sizable. The lawyers are looking to base damages on products’ sales. While companies do not typically break out figures for individual items, Chobani’s revenues are expected to total $1.5 billion this year. The lawsuit filed by Mr. Barrett cites 18 flavors of yogurt, more than half its line.

The lawyers are being selective about where these suits are filed. Most have been filed in California, where consumer protection laws tend to favor plaintiffs. Food companies are already fighting a legal battle there, spending tens of millions of dollars to stop a ballot initiative that would require them to specify genetically modified ingredients.

The lawyers who took on Big Tobacco decided the time was ripe to go after Big Food. Consumers are increasingly conscious of their eating habits as rates of heart disease, Type 2 diabetes, obesity and other health problems rise. State and local governments are also becoming alarmed at the escalating costs of caring for people with those diseases and are putting pressure on food companies.

“People want to put good, healthy, nutritious food in their bodies,” said Keith M. Fleischman, a former federal and state prosecutor who is now working with the tobacco lawyers group. “They are very aware of what’s on labels.”

Plaintiffs’ lawyers realize that critics may counter that their lawsuits do not have real victims.

Mr. Barrett fought tobacco cases for years on behalf of smokers dying of cancer — and lost because juries agreed with the tobacco companies that smoking was a personal choice. Not until he and Richard Scruggs sued on behalf of states, which had spent hundreds of millions of dollars caring for sick smokers, did they win their record settlement.

“Food companies will argue that these are harmless crimes — the tobacco companies said the same thing,” Mr. Barrett said. “But to diabetics and some other people, sugar is just as deadly as poison.”