How much does drinking affect your metabloism?

Ok. I've thrown some tabatas in addition to my training/lifting and my fat has gone down some what. But my friend was lke, "Yo, dude, drinking that beer is going to bring that metabolic rate to a screeching halt." Anybody thinks its that big of a deal? Am i like only gonna burn some calories in my post-work-out state instead of alot of calories because i had a few beers?