Victory for the lawyers who took on the big US tobacco companies and won has whet their appetite for more. Now they are challenging the food industry. About ten years ago, Don Barrett and his colleagues forced the tobacco companies to admit they knew cigarettes were addictive and pay the medical costs of victims. The settlement cost the industry $200bn. Now he is among more than a dozen lawyers who have filed cases against some of the US food industry's biggest players. Mr Barrett's case is that companies are misrepresenting their products, promoting them as "natural" or "healthy", when in fact, he says, they are no such thing. In an interview with the BBC's Susan Watts, he says: "People assume that if a product is legal to sell, then these people are telling the truth about this product... that's what they thought about cigarettes." The lawyer's mission is to make companies stick to the letter of existing laws which, he says, regulators have been too weak to enforce. He says that the Food and Drug Administration has merely been writing warning letters. Around two thirds of Americans over the age of 20 are now obese or overweight, according to the US Centers for Disease Control. Hidden sugars in processed food, Mr Barrett says, are part of that problem, and mis-labelling is key. He cites one example: yoghurt from a food company which lists "evaporated cane juice" as an ingredient, a euphemism for "sugar". His lawsuits are class actions, where the class is defined as every person who purchased one of the misbranded products in the previous four years. "If it cost a dollar and 25 cents, then the customer is entitled to his dollar and 25 cents back," he explains. "And there's a four-year statute of limitations, so the damages in each of these cases is how much have they sold of this misbranded junk in the last four years." Barrett claims that some 25% of products are misbranded in the US. So the scale of damages in these casescould easily match the many billions of the tobacco suits.