> hack your body

This seems a bit of a straw-man.

Almost nobody who's telling you to be more healthy will tell you to eat better without also telling you to exercise more.

Also, it's not "hack your body" it's actually "hack your brain" or, more specifically, hack hunger. That's also why there's so many different diets - everyone's different, and what works for one person won't work for another person. But there are some principles that seems to work for large subgroups of the population, e.g. intermittent fasting / skipping breakfast, eating low-carb, eating more protein, etc.