I'd seem to lose the plot a couple of hours into the round and, soon thereafter, realize I was hungry. If you wait to feel hungry, you've probably waited too long they tell me. So now I always try to remind myself to eat something by the ninth or tenth hole. It seems to help me from having those let downs.
I don't intend to give up on the nicotine, or the caffeine, because I love my coffee, and there's nothing like a good smoke. I come from a long line of smokers, and have inherited the smoking gene. Bobby Jones liked a good smoke. So did Ben Hogan. So, call me old school. But a little protein definitely goes a long way. I'd probably drink more water too. The problem is, it tastes like water.