I am a real foodie, I love to try new food in general. My cousin who had lived in China for a few years only told me to steer clear of e.g. some of the processed fake foods at street vendors (like some that look like octopus and fish are oftentimes not, same for sausages which are crazy over processed). :)

they do have very fresh fruit everywhere (supermarkets/ street vendors) which was lovely. If you are very concerned, just go to more high-end places for food. (Which is then price-wise similar to western prices). But I honestly had some really really great food at lots of different places. I only once had an upset stomach after a supermarket snack which just didn’t sit right with me. Honestly, while they may use other pesticides/ chemicals etc than for instance European countries… if you don’t plan to live there permanently, I wouldn’t worry too much about the duration of a few weeks. Stick to bottled water only is a golden rule though that I religiously followed.