If you eat just carbs, or too high carbs (relative ratios different for everyone) then they are likely to process fast and then you get a blood sugar drop with all the related hormonal results... essentially cortisol (stress/day/get up and go hormone)gets released and even if you don't wake up sleep quality will be effected. If you wake around 3am (think thats about the time for most) its likely blood sugar levels playing a role... (forgetting my times here...)

Interestingly if you don't normally wake at about 2am and you do one night or for a few, there is a very good chance some big mental/emotional stuff is going on in your life... (partly dependent on how decent your sleep patterns are..) We get physical repair from about 10-2 and psychic repair (mental/emotional etc) from about 2-6...

Going to bed at 12 (assuming body even prepared for sleep) you miss out on 2 hours of physical repair...

How is this related to food?? Eat foods that, like sugar, caffeine, alcohol etc and your stress hormones will be up...even if you sleep your quality will be affected.

The right fuel mix (protein/fat and carbs) is different for everyone.. some need jet fuel and some needs diesel... it burns right in your body when the mix is right for your body...

Most people will do better on relatively higher fat/protein at night than relatively higher carbs (relative to what works for them as different times of day are different - like womens monthly cycles - different needs at different times). Some will do better on slightly higher carbs relatively though as a general rule I would say like Kirk and eat more protein and fat...

But like Kirk says.. its finding the right balance for you.

Before bed try eating higher protein and fat for a couple weeks... some earlier and some later and keep track. Then try eating higher carbs for a couple weeks and see what you notice (bet you won't stick with the carbs for a couple weeks)