some people consider themselves carb-sensitive, meaning they're more prone to storing glycogen from carbs as fat. at night, you're going to be burning less kcals, so as the carbs turn to glycogen, they're not being burnt off.
however, its generally accepted that you need to keep protein up throughout the night to prevent breakdown/encourage growth. keep to lean proteins and good fats, cottage cheese is a common favourite, maybe with fish oils as a good fat. ive started using a slow-digesting calcium protein, and have had good results with it, but you can try a serving of whey with a fat to slow it down.
some people can eat whatever they want whenever they want (within their goals) and not worry about adding fat; im not one of them and many advocate pre-bed nutrition.
HOWEVER this is all moot if you train late at night. the post workout meal should always contain the carbs you need to recover, and these will be used up to replenish nutrients in the body. never skip this (i learnt this myself the hard way) or else you training means little. i train around 7pm, so eat my post WO meal around 9, then my protein/fat meal after that.
