We travelled around China (coast and as far west as Chengdu) about 15 years ago. This was pre-diabetes and low carb, even then food was not one of the high points and was a difficult aspect of the trip once.away from Beijing, Shanghai and Hong Kong. However, things are changing fast in China.
Perhaps you will be staying with Chinese people, a family maybe. I think people travelling this way get much better food, it's the hotels that are (were) particularly bad.
I don't know if you are Low Carb, but if you are a carb counter I would be inclined to take some packet carbs (eg oat biscuits) with me for emergency meals, so you know exactly where you are up to and get something to eat.
There are regional varieties in food, though expect noodles, rice and stir fried things. Don't imagine it will be anything like your local take away in UK!
Hopefully there will be someone along soon with more up to date knowledge. Perhaps let us know what sort of trip it will be, eg hotel, family stay etc
Anyway, have a good time, it will be fascinating.
Sally