That's not what I was saying. I didn't say you don't need to exercise or eat healthy, I said you don't need a nutrionist or a wellness coach. Do you know how I know I need to exercise or cut down on sugar? When my belt starts to get tight, when my posture gets bad, when I lose muscle and when I wheeze running up the stairs. Then I know I need to switch the beer for water and take the bike instead of the train to work, problem solved.
Never in my life have I ever wasted a minute installing exercise apps on my phone, reading exercise books, instead I've just gone to public pool and done my laps and for some reason I'm in better shape than some of my peers who seem to spend hundreds of dollars per month on books, peloton courses and exercise audiobooks.
Sure, this sound reasonable. But you needed scientists to figure out at some point that it's optimal for most people to eat some things, and not other. E.g. you can stay lean eating only fruit, but you'll lack some micronutrients.
Also there are some long term longevity effects (or at least people doing studies and claiming such effects).
And even with 'noticing' you feel tired, it doesn't always work, at least not for everyone. Obviously most people would feel suboptimal if they start sleeping 4h/day, for example.
But anecdotally, I dont notice any subjective difference as long as I slept something like 6.5h+. Sometimes I feel a little sleepy but then it goes away quickly.. sometimes I feel like crap till afternoon even though I slept a lot. And making long term observations is hard because it's hard to compare how tired you're feeling now with how tired you were a week ago.
Never in my life have I ever wasted a minute installing exercise apps on my phone, reading exercise books, instead I've just gone to public pool and done my laps and for some reason I'm in better shape than some of my peers who seem to spend hundreds of dollars per month on books, peloton courses and exercise audiobooks.