Wall-E has gone from slightly controversially prescient in 2008 to being clearly WAY TOO optimistic just 15 years later. There's no way those future humans would be that content if they were that inactive and unhealthy.

Gah, it's so frustratingly simple: just don't eat processed shit! That gets you 90% of the way there. Keto, carnivore, vegan, whatever is just the final 10% improvement/tweak on top of that.