With lunch times and things, as naps change you just have to be flexible and do what you can. You start falling into a way things are and just roll with it as things change and as your LO gets older things are more flexible. And, most one year olds are unlikely to wake from hunger in the same way a very young LO is, unless they have truly not eaten.
For instance, as an example, when we moved to one nap, for the first few days that one nap was VERY early and very long - he slept from 1145 - 230 (heaven, I have to say!) So, not ideal for lunch, obviously. So, cut his morning snack (which was usually at 1000) and had "lunch" at 1045. And instead of a light snack when he woke from his nap (used to be at 3pm) now we had a larger snack when he woke at 230. So, no real "lunch" time but he still got his meals in. You just sort of work around it as you need to -> there is no 'right' way except the one that works for you and your LO!
HTH!