THE LIMITATIONS AND REALITIES OF THE HUMAN BODY
THE CONSEQUENCES OF MISESTIMATING ARE HUGE!
WHAT? ME WORRY?
Don't worry the body can handle your ingesting lots of bad fat, not getting enough rest, ingesting acid (using your bones to balance its life-vital Ph), the sludge of inactivity, the hormones of yellow fat in your body, the extra stress on the body of extra weight, sugar whipsawing, the stress that is so extreme today...etc., and etc.
Yes, the body will adjust, at least in the short term, but the long term costs are immense, in terms of the quantity AND the quality of the years.
IGNORANCE IS NOT BLISS!
My reaction to what people think the body can take is: "You've got to be kidding!"
Or perhaps "Maybe you're being unsmart about this and if you don't learn more and respond to what you know you might just, possibly, maybe, kinda be screwing yourself and your life - and maybe even the lives of those around you."
While you surely know many of the things that will "probably" cause harm to your body and your mind, you may not know the harm caused by the harm that is caused by those things that are harmful. There is a large additional cost.
IT EVOLVED ONLY SO FAR
You see, it seems, that the body evolved for us to survive better and longer (at least long enough to procreate and have our children procreate). One of the things it does is cause "motivating chemicals" to have us get back into a high survival mode, which is "high functioning balance" or the more formal name that is considered mandatory to living well: homeostasis.
If we go too far out of homeostasis, the body kicks into gear to get us back to that well functioning range. While being out of homeostasis means our body is malfunctioning in some parts of our body (which causes damage), our wonderful mechanism to get us back into balance causes some long term health balancing parts of our body to shut down (at least somewhat) while the parts needed to put us back together are recruited and put into high gear. Unfortunately, the latter is a very out of balance process, creating damage and/or lower functioning of our immune system and other vital parts. Read, and know, please, please, the essential Homeostasis (Staying In High Functioning Balance) - Absolutely Essential To Living A Great Life!!!.
AND THEN THERE'S THE BRAIN...
Ironically, one of the greatest effects is on the functioning of that great organ the higher brain, which is our secret to being able to achieve extreme happiness, competency, and a great life. But if the higher brain doesn't function well, it sends signals to the body and the primitive brain, which then go into gear for a good cause (rebalancing), but which mostly will cause further damage to the body and the mind. See The Psychological Damage Of Being Tired Or Out Of Balance - More Costly Than You Think! Couple that physiological-psychological phenomena with our failure to see the costs of our behavior and the costs of misbeliefs and you get the huge costs of STRESS, the deadly monster behind the curtain. See The Effects Of Stress - It Ain't Worth It - A Cost You Don't Want To Pay! The effects are far greater than you might think! You might call that a psychological-physiological phenomena (the cousin of physiological-psychological phenomena) - but it goes "both ways" - again, in a vicious downward spiral.
The reality is that there are consequences to what we do - and our body or some mystical force or entity will not save us from them. You've absolutely, if you want to be life-productive and happy, got to learn how the body works and to honor that with actions that have it work better, in consideration of reality!
This is essential, not optional. (Unless you insist on being "unsmart" about it and failing to consider the loss of your life as being serious - or at least a big portion of it - in terms of number of years and the number of years later in life that can be fully healthy and the lower level of life and quality of life that you'll be living as you less healthily limp along through the years, not feeling as good as you can feel, not being as productive as you'd like to be, being more stressed that is tolerable, escaping and numbing oneself to experience less of life....
Are you willing to voluntarily incur those costs in some fantasy that it won't matter much what you do????!!!! (Or in the myth that you can't manage to Change from bad habits?)