If you want a nice introduction to why a proper plant based diet is in most cases better for longevity listen to this interview. The 2½ hours are really rewarding and you'll get some very important (live-prolonging) information:

https://www.youtube.com/watch?v=d5B0rlNvhog

This 7 min excerpt from the interview briefly touches why changing our diets is imperative for the survivability of future generations:

https://www.youtube.com/watch?v=W8rtyomVu88

The podcast of Simon Hill is called "The Proof".