Joe's Crab Shack is under fire after a health group claims the seafood chain lied about its use of trans fat.

The seafood chain advertises that it uses "zero trans fat oil," but the Center for Science in the Public Interest said that's not the case.

The nonprofit health group said a lot of Joe's Crab Shack dishes have loads of trans fat exceeding the recommended two grams.

"Seafood can be healthy, but entrees at Joe's Crab Shack are swimming in artificial trans fat," according to an April 15 article posted on the Center for Science in the Public Interest's website.

The U.S. Food and Drug Administration has labeled trans fats unsafe and has said if it was removed from food, it could prevent 20,000 heart attacks a year.