The suit was filed against the Pepsi-Cola company, Coca- Cola Company, and Doctor Pepper Snapple Group.
Study: Drinking one soda a day adds up to 52 pounds a year
It accuses the soft drink makers of misleading consumers by advertising diet drinks that are sweetened with aspartame, which does not help in the body's ability to metabolize calories.
The lawsuit claims that consumers could mistakenly believe drinking diet soda will assist in weight loss or management.
The Calorie Control Council, whose members include manufacturers of artificial sweeteners including aspartame and the makers of diet soda said "Reduced-calorie products are an important tool in helping consumers improve their diet and lose weight".
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