Hi Charlene,
I think that you will find that
Walt Disney World is incredibly accommodating to those with
dietary restrictions, whether allergies or other limitations. While I am not aware of any specific discounts for those whose consumption is limited by gastric bypass surgery, I think you will find that your needs can be met in a satisfactory way.
Former Disney Parks Moms Panel member Anna, who had gastric bypass surgery a few years ago,
offered this answer to a similar question a couple of years that may be useful to you.
You likely will want to avoid the buffet restaurants, which charge the same price for each diner, regardless of how much or how little you eat. Those will not be good values for you. As Anna noted in her answer, you may be better served by looking at children's meals in the counter service restaurants and appetizers in the table service locations.
I find many healthy quick service options in the World Showcase at
Epcot, especially in Japan, Morocco and Norway.
Thanks for stopping by the Disney Parks Moms Panel with your question, Charlene. I hope you find great dining options to make your vacation as relaxing and comfortable as possible. Enjoy!
Wilma