Dont wanna sound incompetent...but what ?
Like can you tell me what to do and what not to do?
I'm saying maintaining healthy intake is gonna be difficult if the people around you don't behave similarly. By advertisement and restaurants etc, one's going to crave the unhealthy food since they're yummy.
If you're someone capable of enforcing healthy lifestyle (like a government official or some sort), imo it's a much better chance to achieve personal health. Either that or by education or persuasion, but i'm using "forcing" since it's a practical example for results.
Diet helps a lot, but if it's in your genetics there's really no avoiding it no matter how well you eat. My aunt was a fitness nut and vegan, she still got cancer.
If it's in your genes, you still have a chance to cover it, since food and lifestyle are components of epigenetics, and epigenetics can guide the genetic codes to manifest or not to manifest. i've read that how we should do our dietary method, though, is really personalized to our own microecosystem and genetic pattern.