Food Budgeting

In terms of spending on food, I've long thought of there being a natural and obvious division between eating out and buying groceries.

Now I'm beginning to wonder if there shouldn't be a third in-between category of snack food. That wasn't not as obvious, clear, or natural (no organic pun intended). Some snack foods either straddle a line between the two or inhabit a gray area.

There's also the question of whether eating is better focused on meals or snacking anyway.

I tend to need a lot of protein in the morning. What to do about afternoons is a bit more of a mystery to me, but I tend to need something to power through to bedtime. Suggestions welcome.