Well..... I can share what I did during our last trip. I did gain SOME weight, but certainly not a large amount (under 5 pounds) and I felt good about it when I got home. The REAL problem for me in the past has been getting BACK ON PLAN when I get back from a trip. My BIGGEST suggestion is to plan an exact time/date to GET BACK ON PLAN when you return.... best case scenario is the morning after your return.
I lost 40 pounds before our 2004 WDW trip... but I didn't stay on plan when I returned home and I didn't lose any more weight and I slowly, but surely, regained about 20 pounds (over the next few years).
I lost 35 pounds before our 2008 WDW trip... I gained a bit while we were there, but I got RIGHT BACK ON PLAN the day after we returned! And I continued to lose and I am still going strong. It was really hard to get back on plan after eating rather freely for 10 days, but I am SO proud of myself for dong it and it has made all of the difference in the world.
As far as eating WHILE IN WDW, my plans were pretty basic. I shared lots of meals.... or I would eat a side dish from one child's combo meal, a side dish from another child's combo meal, and maybe a small side or some protein that I ordered for myself. A cup of water with that and I was good. The kids didn't mind giving me their vegetables usually and they still had enough to eat... especially if they got dessert. I drank lots of water. I did have a few Mickey Ice cream bars, but sometimes I just had a bite of an ear from my child's ice cream and that was enough for me.
I have a long post on here somewhere about some of my other strategies. I will try to find it and share it here.......................P
Okay.... here is what I posted on the Summer Club a few weeks ago. Maybe it will be helpful.
#1. Share meals whenever you can. The portions, especially at counter service places, are large. Sometimes my kids would order some sort of combo meal and not like one of the items it came with (usually something healthy, like the hot vegetable, side salad, or such). If they both gave me their unwanted side and I ordered myself a small salad or veggie burger or such, that was enough for me. It saved me calories and $$.
#2. At buffets, eat ONLY what is TERRIFIC. We had dinner at CHef Mickey's. After filling up on salads, I went back and took small portions of things that looked wonderful, like Prime Rib, garlic mashed potatoes, and a few other things. I ate what was wonderful and ignored what was not so great. Same for desserts.... I got three to try... one KeyLime cheesecake bite, a small scoop of bread pudding, and some sort of oreo cookie-mickey ear thing. The Keylime was tasty, the bread pudding was SUPER and the oreo thing was NASTY. I only had one nibble and that was ENOUGH. I didn't finish it. I only went back for another small scoop of the bread pudding. I was very satisfied, not STUFFED and had truly enjoyed everything I ate.
#3. Bring along some foods from home to help out. I brought along FiberOne bars and a few other things from home. They came in handy both for breakfast and for quick snacks in the parks. Don't get me wrong, I had my share of Mickey Pops, one Dole Whip, and I shared a caramel apple with DD, so I definitely had treats during the week.... just not several per day. Sometimes just a nibble of someone's ice cream was enough to satisfy that desire.
#4. Keep hydrated. It is easy for you to mistake thirst for hunger, so ALWAYS keep drinking..... and speaking of drinking...
#5. Watch the "liquid calories". It is easy to overindulge in those fancy cocktails and such while at WDW, but they are full of calories. Alternate your alcoholic drinks with water or seltzer to keep you from going overboard.
#6. Look for the better choices available, no matter where you are eating. It may take some searching, but most place you can find a salad, side veggie, grilled chicken, veggie burger, fruit salad or fruit side, etc. Make up your own combo meals from these items if necessary. Avoid anything that you KNOW is full of fat and sodium, like hot dogs, burgers, fried foods and FRIES. (Fries are not that special...you can get them anywhere, so no need to spoil your diet at WDW over something like FRIES!). Save your calories for SPECIAL foods like Dole Whips (or whatever your "special-only-eat-at-Disney food is).
#7. Set a time, date, etc when you will get back on program when you return home. Usually it would be best to say "the morning after we return." Otherwise it is easy to keep eating in "vacation mode". This is the voice of experience speaking and so I KNEW on this last trip we took that I had to TELL MYSELF that the morning after our return it was back to "business as usual" with my Weight Watchers points and exercise. It would have been TOO easy to just keep putting off getting back on program, but since I had set myself a "rule" before we even left, I knew when I had to get back to real life!