he should up his own calorie intake himself.
obviously with an exclusively breastfed baby it's difficult to get them to take in more milk, however as he grows he will actually do this, and you wont' really know. You might even go through a stage of thinking you're not producing enough, which is actually that he's taking lots and you don't feel full because of it.
as they get older the become very efficient at feeding and feed for shorter times but take more milk. Practice makes perfect!!
Rosie started waking more in the night as she got near to 16 weeks, and from not waking at all between 8 and 16 weeks she then started waking once, and then twice and then when we got her onto solids at 24 weeks she stopped. NOT that i'm recommending you go onto solids just yet.
I found the other way you can increase calories is not to feed more frequently during the day, but you can cluster feed every 2 hours at night OR what I did which was to express after the first feed in the morning. The milk is very calorie rich then and there's usually plenty of it. In addition taking an expressed amount (even a fwe ounces) will help increase the milk available through the rest of the day. I then gave that expressed amount after she'd finished feeding at her dreamfeed, so she was absolutely totally stuffed as full as she could of milk. that was how we got her going from 10pm until 6 am in the frist place actually.