The best time to eat is very subjective and depends on a lot of things. Some things to consider are who you are going to be with at the parks, any eating issues (diabetes/hypoglycemia/etc), park hours, and the time you are going to leave in the morning.
I will give you my situation in which I have me, my husband, and two kids (now 6 & 5). I am hypoglycemic and get REALLY cranky if I don't eat and my son has taken after that

So given that, I always eat 3 medium meals, and 2 large snacks during the day normally and I encourage my children to do the same. But at Disney, you are walking a lot and burning a LOT of calories (I've never gained weight there no matter how much I've eaten) so be flexible and if you need a snack - stop & get one even if you think 'oh, i'll be eating in an hour'. Ok, so we eat a light breakfast in the room (or on our way to the parks) and have a snack if needed before lunch. We eat lunch BEFORE 11:30 am because that is usually when the rush starts. We leave the morning park around 1 pm, and this is where it counts who you are with - we need a NAP or downtime! So we must schedule that in. After nap/downtime, we head to the pool where we have a snack and swim to refresh. We have usually eaten CS around 6pm when we get to the parks. There doesn't seem to be as much of a rush for CS restaurants in the evening. This year, we will be doing the
DDP for the first time and I do have ADRs for around 6pm each evening. This gives us enough time for our afternoon siesta but not too late that we are all starving.
OK, that said, maybe you are travelling with 4 adults who would rather eat dinner at 8pm. If that's the case, maybe you eat after the lunch rush. But I will say this, if you don't have an ADR for a lunch TS, and that means you need a CS for lunch, try to avoid the 11:30 - 1:30 rush.
I will give this piece of advice about eating though - don't wander around trying to figure out what to do. This is the surest way to get everyone hungry and cranky. If you aren't sure, and you need to eat, just stop and eat - even if it is grabbing fish 'n' chips in Epcot's England and sitting on a bench
Hope that helps and have a great time!