Frito-Lay introduced a fat-free potato chip called Wow! in 1998 that was marketed as fat-free. It generated initial sales of $400 million. The secret ingredient? The fat substitute Olestra, which the FDA determined caused cramps, diarrhea, and uncontrollable anal leakage. Sales plummeted to $200 million and Wow! was rebranded as “Light” in 2004.