During my 5 day trip last year we only did counter service. Since we drove down, we were able to bring food with us to have in the room.
None of us are big eaters so we had breakfast in the room. Usually bagels & fruit. We did counter service for lunch and usually bought 2 meals to share between the 3 of us or my 62 year old mother would sometimes order of the children's menu. We then could "snack" during the day without feeling we were overeating. We would then grab counter service again for dinner or have fruit,fresh veggies, crackers & cheese for a lite dinner in the room.
Counter service doesn't always have to mean burgers & hot dogs as most poeple think. Disney has some of the best quick service food that is a real meal. Wonderful salads, rotisserie chicken, pizza, wrap sandwiches, meats with vegetables (Tusker House), fish & chips, and the wonderful, more exotic options at Epcot.
In the 5 days we were there, I only at 1 hot dog and NO hamburgers. I rarely got fries because most places let you get carrot sticks instead. I don't think I ate the same thing twice.
We didn't spend half as much on food as I had budgeted just by sticking to counter service and had more time to enjoy the parks.
This year we have schedulee one sit down character breakfast as a special treat for my nephews who we are taking with us. Other than that, it will be counter service & the food court at POR.