50/50

I think that 50% relies on your lifestyle if you spend more time indoors or in man tampered areas your body won't develop naturally and the other 50% is the diet of course doesn't really matter what i eat raw meats and plain vegetables/fruits. But I think this 50/50 makes up your development since almost all animals are opportunistic and none look deformed after scavenging for "human" foods due to their exposed natural lifestyle.