don't let anyone tell you what to do with your life because everyone is improvising as they go along and absolutely no one really knows how life works in general.
i am 33, never exercise, sleep poorly, am autistic, smoke and drink almost every day. the first photo is my grandfather at 40 years old, the second is me currently. am i saying you shouldn't take care of yourself? no, i'm saying the world will function regardless of your actions, you can plan all you want but life has its own plans.
believe me, i would like to talk to you about what dna telomeres are, what historical materialism is, the class struggle, determinism, what a body without organs is, and how the power of an unsatisfied subconscious desire works... the world is complex, but we spend our lives looking for answers when what really matters lies in the questions.
if you need to be happy you will never achieve it.
p.s. i have nothing against the original post. i respect their views on health and longevity. my post is just another perspective on the unpredictability of life and the importance of living authentically.