Thanks to all for the awesome posts. Sorry I didn't respond right away, just got home from work.
I was figuring I was probably alright with an occasional short day. I tend to hit mid-to-high on my range otherwise, so those days didn't seem like they were a bad thing.
Also, regarding the eating every three hours thing, sure that would be ideal. However, we live in a society where that isn't an option. When I work an 8 hour shift, I cannot actually eat every three hours. I'm in retail, and breaks don't always come on a timer. So that's simply not possible for me. Sure that's the body operating at peak, but I've never seen that as a hard-and-fast rule.
I do keep track of it, and the closest together they've been in ages was twice in a week where I wasn't hungry, but I was high-stressed, recognized that, and ate something light anyway. Typically it is once every two to three weeks that I just don't want those last hundred or two hundred calories.
I will make a note on my journal when it happens, and if it ever does seem to be more frequent, or if I'm *way* under, I'll definitely bring it to my doctor.
Again, thanks all!