Chemically, it doesn't make sense that there would be any harm in the first place. With properly functioning kidneys, the resultant chemicals get filtered out e

Chemically, it doesn't make sense that there would be any harm in the first place. With properly functioning kidneys, the resultant chemicals get filtered out extremely quickly through the urine. It helps that most diet colas are also diuretic. The resulting methanol and/or formaldehyde don't stick around to cause harm. This is empirically backed up by the lack of adverse effects over massive populations and over decades.