I know that my pre-schooler can only handle about 5 hours in a theme park without a long break. She also eats about every 2 hours or becomes a cranky tyrant. So looking at my notes for the fall trip..
We plan to attend MK EMH and I booked dinners around 5:30 at monorail resorts. So we'll plan to arrive at the MK around 7:30 and stay until midnightish. I'm planning to pick up at least one CS meal for the 2 pre-schoolers to share. It might end up being a snack instead - but the most likely is that we'll get a bunless hotdog and fries at Caseys. One can eat ketchup with fries and one can pull the innards out of the hotdog. Then they can decide they both hate crackerjack.
We have an AK EMH too - Since it comes the day after MK's evening EMH I don't expect the little ones to be awake for it. Their grandparents will go though and the kids, my sister and I will meet them for a late breakfastasaurus (10:30 I think). Then we'll spend some time doing trails and generally having a low-key AK day.
We also planned meals around MK's morning EMH - park opens at 8am to on-site guests, and I think that by 11 it will be jam-packed. So I made 11:30 ADRs for Crystal Palace. We'll stop and eat on our way out for a mid-day rest. I'd get a mid-morning snack somewhere too - but the pickings are really slim for that - so it will probably be snacks from the diaper-vest of doom.
I didn't bother planning meals around Epcot's EMH - other than that I assumed if we did Epcot morning EMH we'd take an early break and planned an earlier than usual dinner. Hrm, no - I'm wrong. I do have an Epcot evening EMH on here - and it says we'll eat at Coral Reef at 5:30 - presumably on our way in for a late evening. I'd give 50/50 odds that we actually make that meal though.
I don't like interrupting park touring for a TS meal. Between getting to the restaurant a little early, waiting for a table, having a leisurely meal, etc - it takes 1.5-2 hours. That's generally long enough for me to realize how tired I am if we've already put in a few hours at the parks. So I try to schedule major meals either on the way in or the way out.