Joining a field already crowded with such non-caloric beverages as Coke Steam and Hollo Yello, PepsiCo announced the creation Monday of Pepsi Negative-220, a diet cola that burns twice the calories it contains. 'You'll love PN-220 for the super-slimming rush of thyrotropin, PC1 enzymes, and that zesty hint of lemony leptin that zaps away fat, muscle tissue, and some nerve sheathing,' PepsiCo spokesperson Ned Caen said. 'But you'll drink it for that refreshing cola taste.' Despite an FDA label warning of potential cardiac arrhythmia, renal shutdown, intestinal necrosis, and spontaneous erosion of the meninges, plans are underway to debut Pepsi Negative-220 in early October. 'For radical and uncompromising weight loss, it's the cola,' Caen said. 