Cancer, diabetes, stem cells
These are all incredibly complex problems that aren't easily solved even with massive investment. This is like comparing sending a rocket to the moon and building a self-sustaining moon base. Most effective medicine has been about boosting the body's ability to do its job or using naturally derived chemicals, vaccines, pain killers, penicillin, etc etc.
We can't really do that with cancer and stuff like aging. We've been using chemicals derived from millions of years of evolution to do delicate, effective work. Now we're trying to build our own but we're nowhere near as precise yet.
My comment was in response to people who did lose weight but gained it back. The point is that people can lose weight, but most can't handle ultra-processed food in moderation. Rebounding is not fatalistic, it is a consequence of returning to a previous diet. Saying 90% regain their weight doesn't tell the full story.
You can make the same argument for alcoholism and domestic violence. We can acknowledge societal factors of behavior while still calling a spade a spade. Childhood obesity is abuse, domestic violence is abuse, I don't care why people do it. The fact that you won't label this is just disgusting. Permanently fucking up a child's growth, hormones, and self-esteem would be considered the highest form of abusive if the method was anything but food.
To be clear, I'm not saying these parents should be arrested. But it is abuse, full stop.