The comedian did an interview with "The Art of Dialogue," and when they posted a snippet of it on Friday ... all hell broke loose on Twitter. We will say this ... what Aries opined on is pretty mean and the tone of it completely overshadowed the point he was trying to make.

AS was asked if he thought Lizzo's music was a standout in this day and age -- but he immediately pivoted to an insult. He says he can't get over the fact that she "looks like the s*** emoji" ... and then continues to say she has a pretty face, but a terrible body.

Aries goes on to say the praise she and others -- whom he considers fat/unhealthy -- is ass-backwards ... adding that if people really cared, they'd send a different message to these same stars (like Lizzo) ... one that's a bit more health-conscious and honest.

Bill Maher echoed similar sentiments, but did so more tactfully. Here, Aries gets down in the gutter ... and he's paying for it with some of these Twitter responses on Lizzo's behalf.

Many are pointing out the irony of Aries criticizing Lizzo's weight, noting he himself isn't the best shape -- AS also pointed that out as well, FWIW. Still, he's being met with the same viciousness he tossed out in Lizzo's direction ... with many mocking his own looks.

Others are even arguing Lizzo is in tip-top shape -- seeing how she can dance, sing and play the flute within any given set. They say being "fat" doesn't mean being unhealthy.