I'll readily grant that the universal free school food is a huge improvement on the US swill, although this too has its share on unhealthy practices: mandating that everything served has to be eaten whether you're hungry or not or you like it or not (kids are regularly told that sukikirai, liking/hating foods, is not allowed), and the mandatory milk & milk bun for that sugar kick. At least whale meat has become too expensive to feature regularly anymore.
When you cook it yourself even with very little salt and reasonable spices for a baby, the result is so much better. We can see how much our little one enjoys cooked stuff vs bought ones, so we stopped quickly with those. It takes some time, but covid is actually helping with this particular thing right now. Thank god our kindergarden has proper chef who actually cooks and not just reheats frozen stuff from cheap retailers.
Its a bit sad that even in 2021 we can't really manufacture en masse reasonably processed food that contains just the food ingredients and tastes at least reasonably.
My daughter and one-year-old grandson live with me, and ever since he started eating solid food she has been feeding him exclusively homemade, vegetable-centric meals. When preparing the food, especially at first, she referred to guidelines for ri’nyū shoku (“weaning food”) in the Maternal and Child Health Handbook issued by the government for all babies [0, 1] as well as some cookbooks she bought. The emphasis of ri’nyū shoku guidance is on handmade, nonprocessed food; my daughter has yet to buy any commercial babyfood. She hasn't been able to have much interaction with other young parents (for obvious reasons), so I don't know how typical her approach to babyfood is. But my impression is that she is not unusual.
For older children, the government promotes something called shokuiku (food and nutrition education, [2]) that is incorporated into the school curriculum and is coordinated with the food that children actually eat at school. (Most schoolchildren eat school-supplied hot lunches.)
The specific guidelines for ri’nyū shoku and shokuiku seem to reflect both scientific research on nutrition and a nationalist nostalgia for traditional Japanese diet and eating customs.
[0] https://www.med.or.jp/english/journal/pdf/2010_04/259_265.pd...
[1] https://www.jstage.jst.go.jp/article/jaih/27/2/27_121/_pdf
[2] https://www.maff.go.jp/e/policies/tech_res/shokuiku.html