Hi Robert,
Thank you so much for visiting the Disney Parks Moms Panel with your question. We on the panel love helping guests to plan magical vacations!
Walt Disney World offers three different
dining plans: the Disney quick-service dining plan, dining plan, and deluxe dining plan. Before we take a look at those, you mention that your family does not eat very much in the theme parks. Each of the dining plans include not only dining locations inside theme parks, but also at Walt Disney World resort hotels and Disney Springs as well. At the bottom of the page a linked, there is a place to "choose a restaurant." By selecting the plan in which you are interested, you can see all of the options for dining on that plan, including the location.
To your original question, Disney does not offer a snack plan. The closest match to that would be the
Disney quick-service dining plan. Using this plan, each member of your traveling party would receive two quick-service meals and two snacks per night of your stay. You would also each receive a resort refillable mug. By spreading these quick-service and snack credits out across your vacation, perhaps this dining plan would work for you.
I hope that these thoughts are helpful for you, Robert! Have a wonderful time planning your magical vacation, and please let us know if we can be of any further help.