You can always stockpile certain imports like grains and oil. If they gonna try to starve China then it might as well just go to nuke war.
I believe Chinese government already stockpile a year worth of grain and maybe some meat. Do you like the taste of old rice?
There are multiple ways to starve China. US can issue tons of fiat money to buy up all the grains on the market. US can sanction anyone who sells grains to China. US can sponsor (behind the scenes) pirates to halt Chinese shipping. Are you gonna nuke the US for that?