With all due respect, I’d suggest you do more research on this subject. BMI was debunked many years ago. I highly recommend this article. https://www.npr.org/templates/story/story.php?storyId=106268439

Money has everything to do with it, both in ways I mentioned and ways I haven’t touched on here. Money is how we access healthy food. It’s how we access the time to cook it. Blaming it on the parents is a gross oversimplification that indicates you have not read up on this issue.