Much less than I used to. 5 years ago I was 17, and the scrawniest kid you can imagine; I discovered the gym and bodybuilding, and went on a crusade with it for a couple of years. I went from weighing 60kg at 17 to weighing nearly 80kg when I was 19; I'd eat something like 4,000 calories a day or more, and packed on a lot of mass.
This was fine back then, my metabolism was crazy and I hardly put any fat on. But these days, even if I exercise constantly, I still have to be mindful of what I eat or I get soft. I'm sure no-one would ever say I've been overweight, but it's noticeable to me.
These days I probably get about 2,500 calories a day, try run 5km at least every other day, and do weightlifting so I don't turn into a noodle. I'm at a good weight of just over 70kg now, and whilst I sometimes miss feeling like an absolute beast, I'm in great shape and now I can see my cheekbones, so it's all good.