The Hangover Part III star Zach Galifianakis revealed in a recent interview with Conan O'Brien that he quit drinking after a life-changing incident on Manhattan's Lower East Side and resultantly lost a lot of weight.

In response to O'Brien's compliments on dropping some pounds, Galifianakis said his weight loss was merely a byproduct of quitting drinking.

Alcohol has been shown to cause weight gain for several reasons. First, alcohol has tons of calories. Second, alcohol increases your appetite and therefore food intake. And third, alcohol alters blood glucose levels in a way that promotes weight gain and lowers metabolism.

"I was getting in too much trouble with the drinking stuff," said the breakout star of The Hangover series.

Galifianakis told the late night talk show host that he was cut off by a man driving a Jaguar while walking home from a bar after drinking a lot of whiskey. In response to the driver's abrasive actions, Galifianakis slammed his hand on the car as hard as he could and walked off. What ensued afterward was enough to make the actor quit drinking altogether.

"I turn around, it's two huge 6-foot-6 guys [from the Jaguar]," he recalled. "They both, at the same time, spit in my face! I don't know if you've ever been spit in the face non-sexually, but all I remember is being so stunned."

Galifianakis then reached into a trash can, grabbed a beer bottle to throw at the Jaguar as it drove off, and missed. "That's one of the reasons I decided to cut back," he joked.