There's a difference between malnutrition due to scarcity and malnutrition due to overconsumption of the wrong nutrients, though.
Kids need to be taught proper eating habits and school lunches need to be sufficiently nourishing and not pizza/chicken nuggets/cheeseburgers/tacos/pasta every day of the week like they had when I was younger.
It's just as easy to have a diet of too much fried/sugary food in China as it is in the US. The only sort of scenario that I don't believe exists in China that happens in the US is government subsidies for producing corn/HFCS.
You didn't get the prepackaged "grilled cheese"? I am not joking, this was a real thing my real school really served. I was astonished that such a thing was real.