Well, winter comes right after Halloween, so I always pack a few of those tiny chocolate bars that the trick-or-treaters didn't get. Just pop them in my mouth and let them melt until chewable.
For "real" food, PB & J on whole wheat loaf bread is great. As someone said earlier, the baggie works well as a handle.
I generally don't do hot soups or other food, to avoid the weight of a thermos. I heat my water before putting it in the Nalgene. One goes in a wool sock in the pack, the other in a cozie on my pack belt. It sits in front of my right hip and doesn't get in the way.
I try to avoid high sodium foods and caffeine because I'm an old fella.