Given that there will be no actual food, you could eat insects and wild edibles if thats your only option. The other choice would be starvation or fight for remaining actual food.
Also, would all water become radioactive? Yeah, that might force you to collect rainwater.
Of course, eating insects and wild edibles will make you skinny like Eugenia, but at least you wont be hungry and starve.
Also, you wont be a threat to anyone, so increased chances of survival.