Well, the Washington Post newspaper wrote an article fairly recently about Japanese 給食 (school lunches).
The article is here.
Basically, it says that school lunches in Japanese schools are healthy and delicious.
They are like home cooked meals made with locally grown ingredients, unlike the fast-food type of lunches that I ate in schools in America.
Also, the students serve the food to each other in Japanese schools.
having raised three kids in Japan, I know that students in Japan eat proper food in school.