I know this feeling well. This is a false sense of sharpness caused by undereating. You dont feel hungry or tired, just energized, light and strong.
I say false sense of sharpness, because you're actually not that alert. Yes, you can push yourself more, but your brain is in flight/fright mode and not thinking rationally.
May I point to one paper of many that show proinflammatory cytokines to be reduced due to intermittent fasting?
“Under controlled conditions, [diurnal intermittent fasting] led to significantly decreased plasma levels of cytokines (IL-1β, IL-6, and IL-8), particularly IL-1β and IL-6 across 24 h.” – The effects of diurnal intermittent fasting on proinflammatory cytokine levels while controlling for sleep/wake pattern, meal composition and energy expenditure, 2019: https://journals.plos.org/plosone/article?id=10.1371/journal...
We tend to eat up mechanistic reports that make us feel good about our preferred lifestyle, but in this topic you’d want to find experiments that increase alertness during IF (something that actually confirms an endpoint). Maybe they exist.
A classic example is the “antinutrients in plants” mechanistic fad while plants in a diet actually increase all health outcomes when put to the test.
Exercise causes a huge inflammatory response too. Thankfully we know better than to stop the analysis there.
The exercise inflammatory/antiinflammatory control loop is indeed wildly interesting! As are the nuances of how the interleukins work.
I deeply encourage people to read the science. And indeed all of it.
As you said: Maybe they exist. They probably do – if the substrate of under-funding things has allowed them to come into existence. There are studies that show general health benefits from intermittent fasting as I recall.
It’s also worth paying attention to one’s experience of the world, and to not discredit it. There’s a distinction between following a fad, preferring a lifestyle, wanting to feel good about it – in a social sense I guess? …versus, say, noticing a sense of clarity whole watching one’s bloodwork results improve.
Read papers. Mostly science. Not too carefully.
Mechanistic ones too. Mechanistic ones too! From personal experience, I ask you to believe me when I give insulin glargine as a clear example of the molecular biology of something clearly showing that a certain medicine is literally dangerous. The zoomed-out general health studies smooth over the substance’s obvious capacity to abruptly flow out of bolus sites and dump 24 hours’ worth of insulin into the bloodstream. It’s obvious from the molecular biology and the anecdotes of horrible blood sugar crashes and people dying in their sleep. Please don’t take too much salt with the mechanistic studies. It’s mechanics all the way down.
Irrational thinking seems unlikely. When glucose deficit, the brain functions fine on ketones. It might be you're experiencing your brain running on ketones.
I say false sense of sharpness, because you're actually not that alert. Yes, you can push yourself more, but your brain is in flight/fright mode and not thinking rationally.