Health

difficult for most sans any and all forms of fish/animal-based supplementation. Add to that the need for adequate vitamin D (which you apparently supplement naturally with outdoor physical activity) and weight-bearing movement--all of which you seem to work to make sure you maintain.

I'm absolutely in favor of eating more plant-based foods. Strict absolute vegan diets, considerably less so for many/most people. And yes, of course not smoking and good genes make a difference as well, but diet is incredibly important.