Hi there, Caroline!
Glad to hear you are planning a well-deserved break!
Advance dining reservations are
strongly recommended. walt Disney World allows reservations to be
made online and via telephone at (407) WDW-DINE 180 days prior to a Guest's arrival at his/her Resort, and people definitely take advantage of this offer.
My advice is to figure out your "A-list" of choices and create backup options, just in case, and get ready to make arrangements. You'll need your confirmation number and, for some restaurants, a credit card. This card will not be charged in advance; it is used as a guarantee that you'll keep your reservation, and if you do not cancel 24 hours in advance, you'll be assessed a $10 fee for each name on the reservation.
Every restaurant offers multiple healthy options, and swaps are readily available (fruit for fries, and so on). The chefs are more than willing to work with each Guest on an individual basis, so you can rest assured that your dietary needs will be met.
Have a wonderful time!
See you later, celebrator,
-Deborah B.