Regulations for food mailed to China

I’ve searched high and low on the Internet, but I must not be searching in the right places. Perhaps you folks can steer me in the right direction.

I have a friend who has moved to China for a year to study kung fu (it sounds like the setup for a joke, but I kid you not). He’s in a rural area and the food at the school, I hear, totally sucks. I’ve been commissioned to send foodstuffs if at all possible, namely peanut butter and chocolate, but I think anything non-perishable is welcome. My question is this: before I invest a lot of money buying and mailing food, are there any regulations I need to know first? I’ve been told that customs might search my package, which is fine, so long as it gets there.

Any help would be appreciated. Thanks!