I lived there for two years, ate in some of the shadiest places around (we're talking cockroaches on the walls...) , in various cities and not ONCE got any kind of food poisoning. Not even an upset stomach. Talking about shit pumped into animals - I'd say the west is just as bad (if not worse) when it comes to stuffing animals with antibiotics. Preservaties, E numbers and god knows what else have been staple of our diet far, far, longer than they have over there. It's no paradise (what is?) but it's not that bad either. You probably won't need to pack the shotgun.
I did eat in a noodle shop, where you shared a table with 7 other people and it did not look that great and I was the only foreigner in the place, but it was cheap at less then 1RMB, which was about 60p (about 90c), did eat at a few places in and outside Shanghai in Villages with a population of a few hundred and found the people very friendly (and they did not rip me off or try to rob me), took far too many photos though...
In the US in battery farming they pump them full of crap so they grow fast and can't move. Can't move = no energy lost through movement = bigger animals.
Fast food nation is a fantastic book to read... anyway back on topic... er don't drink the water, it's clean but it tastes of crap.
I got sick in China. Was eating in a nice Japanese restaurant and I avoided anything raw. Only ate anything deep-fried and crunchy. My significant other had a bowl of noodles and stopped eating it after a while. She said it tastes off. So I tasted a bit and went "<shrug> tastes ok to me". So I ate the leftovers. Next day, I got really sick. Took 2 to 3 days to recover. I guess I'm no noodle expert.
Unless they are eating dogs. Which they beat to death to enhance flavor. I'd only eat cooked vegetables and drink something with boiled water like tea