You can definitely eat at WDW for 100.00 a day. We did it with less than that!
We (myself, DH, and DS) stayed at POFQ for 7 nights at the beginning of March.
BUY THE REFILLABLE MUGS!! Big money saver, IMO.
$11.99 each x 3 = about 37.50 w/tax. After 3 refills, these mugs paid for themselves. Believe me, we were filling up these babies every chance we got.
Breakfast usually consisted of beignets (yum), coffee for DH and I, hot chocolate or juice for DS. We shared the container of six beignets.
6 biegnets--3.99
coffee-- free refill
juice--free refill
Total--about 4.50 with tax
Lunch was grab and go items such as turkey legs, or hot dogs.
Never anything over 6.00 each. We didn't even eat lunch every day.
Dinner was usually something from the POFQ food court.
Items would range from a cheeseburger platter from around $7.00 to a chicken/rib combo meal for $10.00.
We didn't get dessert with our meals because we were not on the
DDP.
We went to two TS meals--O'Hana's and Chef Mickey's breakfast.
There is no menu at O'Hana's. Service is family-style. It was a TON of food for 3 people.
3 adults (DS is 12) cost us around $65.00 not including tip.
Chef Mickey's was about the same.
For snacks, we went to DTD to Goofy's Candy Co. and got caramel apples for around $6.00 each. They have cheaper snacks there, though.
We also went to Riverside's gift shop and got bagged snacks there twice.
We used Disney Dollars for those purchases.
Hope that helps you out.
We went to WDW on a very limited budget and felt we got an adequate amount of food for a reasonable amount of money.