Can i still eat junk food when im trying to preserve my voice for singing?

ok well im in a band and i sing...so yah i love to eat junk food like chips with hot sauce or cookies n stuff n ya i realized after getting arrested i started gettin chubby while on house arrest cuz all i ate was junk food n i didnt really practice my singing but now i have 10days left on house arrest until i can get back with my band. but i've noticed my voice isnt the same anymore...so i decided to start working out like running on a treadmill pushups sit-ups simple stuff....an it helps but i was wondering if i can still eat junk food chips,cookies pizzas n **** if i work out everyday like will it ruin my voice?