Bill launched on his HBO show, "Real Time with Bill Maher," jeering at liberals who have made criticism over weight taboo. He scoffs at the Democratic candidates who are fighting for health care coverage for people with preexisting conditions, when he says the most serious preexisting condition is obesity ... yet it's not only overlooked by the candidates, raising the subject is considered bullying.

Maher goes on ... saying we "eat like assholes" in the U.S., putting fried chicken on a sandwich, adding bacon and other ridiculous things until the gluttony will "make my mouth cum."

Bill doesn't stop there ... he notes that the number of shooting deaths pale by comparison to deaths and illnesses triggered by obesity, calling liberals who shun fat shaming, "NRA mayonnaise."

Ahhh, but there's more ... he says being fat is not a birth defect, citing the NYT which reports poor diet is the leading cause of mortality.