We have e-mailed two different addresses at WDW and the Mom's panel and received very differing answers. Here's what we think--- no buffets will allow adult to eat for kid's price (except one Disney mom says The Biergarten did???)
no "take out" from any buffets for a person who eats only a few ounces for a later small meal. most kid's menus are not very friendly for gastric bypass patients-- lot's of fried food and high fat meats as well as sugary desserts. So buffets seem to be out unless you can live with paying full price and eating so very little. Table service seems better fit since one can order just an appetizer or share with another. WDW says no reduction in portion size nor cost. Of course, you can take out whatever you don't eat for later if it won't spoil and you want to carry left overs with you. Disney mom said character meet and greet buffets did allow her to pay only an entertainment fee and not eat nor pay for food. We received conflicting answers about one person ordering from the menu and the other eating something prepared and brought from outside the restaurant. No disney cast member can warm, microwave, or cook anything you might bring in. Also all agreed no adult can purchase and use child's
DDP under any circumstances. Seems Disney is not as accommodating of the needs for gastric bypass patients as they are for other dietary needs, but it is doable with planning and forethought.