> In no way is fasting healthy … while fasting for more than a day or so at most.
The italicized portions are both qualifiers that suggest / reinforce something like "literally no one in human history has successfully fasted."
If you meant "On average, low blood sugar will cause lower metal and physical performance," just say it. Sarcasm and hyperbole don't come across clearly on the internet. It's much easier and more considerate to write what you mean the first time, rather than writing a hyperbolic and simplistic statement and then retroactively rationalizing it.