The better question is what foods would you start eating more of.
And this presupposes that if I were to stop lifting/exercising I decided not to give a damn about my health and appearance.
My diet would consist primarily of pizza, fried anything, ice-cream, donuts and brownies, chips. Any cookies, cakes and what not. M&Ms would be with me always. More ice-cream. I probably wouldn't eat much meat unless it was fried chicken, orange chicken, and shrimp tempura.