In PDN, if you don't bring your own food you are sunk. You are not allowed to go out, at least by MY agency.
I bring a cold Adkins shake to drink for breakfast, which can be consumed during the busy first part of the shift. Sometimes I drink it on the way, depending on the time of arrival, and the distance I will be driving.
For lunch or dinner, I love to bring leftovers. I plan and make enough on my last day off, for a day or so. I have brought romaine salad with raisins, chicken, etc. Really good, and healthy. I like to get that, and any snacks and drinks, ready the night before. I actually make a list, and leave it on the kitchen counter. Then in the early AM, I can just go down the list, throw it all in my cooler, add 2 "ice packs", and hit the road. I can't do any creative thinking at all before 7am.
But these meals take 2 hands to eat. If the patient needs me every minute, I bring a sandwich, and hold it in my left hand. Then I can reach out with my right, and divert him from crawling his way into trouble.
The biggest problem is that I don't burn a lot of calories working in just 1or 2 rooms...not like I did when I ran for 8 hours in LTC or the campus where I once worked. I have to be sure, in some cases, not to eat out of boredom.