I'm not a heavy drinker.

我不是贪杯之人。

His father is a heavy drinker.

他的父亲是一个酒鬼。

He is a heavy drinker.

他是一个酒量大的人(酗酒者)。

But recently I had become a very heavy drinker.

但是，近来我成了一个非常严重的酗酒者。

After making this film, I became more of a heavy drinker.

拍完这个片子我变得更能喝酒了。