There is a McDonald's just before All Stars and another in Downtown Disney.
There are sandwiches, with a piece of fruit (apple, orange or banana) and a small bag of chips at the Boardwalk bakery.
There is pizza at the walk up window at Spoodles.
There are deli style offerings at the Gourmet Pantry in DTD.
There are two Puck's Expresses, one in the Marketplace of DTD and one on the West Side.
There are burgers, hot dogs, soup, ect. at Beaches and Cream in the Beach Club.
There is lunch meat, bread, condiments, snacks, and drinks for sale at the Screen Door on the boardwalk.
There are numerous selections at the food courts in resorts such as the All Stars, and the moderates.
You shouldn't have much trouble finding a light lunch!