After they find out that Nathan's allergic, the whole family goes on a gluten free diet, which leads to a weird competition between Will and Theresa to see who can keep the diet up longer, and for Brenda, who's trying to convince health-conscious Grant she can live without it. Problem is, they're all cheating. Meanwhile, it's all fast food, all the time for Craig and Kenny as they romance two ladies who work at Big Burger.