If I don’t eat some of my food for one of my meals, can I have it at a later meal instead?

I don’t swap between meals. I like to keep my food as part of the meal it’s supposed to be in. As for eating breakfast food at lunch or lunch food at dinner—I don’t do that. I work hard to get what I need at each meal. I think trying to stick with the plan is the best idea, and preparing/packing ahead so you have what you need is an important habit to form.