I believe that pushing the body to limits such as fasting, hot/cold baths, intense workout can help us in the longterm. But for when we need our brains to work at its highest potential in the immediate such as software engineering all those things, how is having a hindrance such as hunger anything but a distraction?
Hunger could be a distraction perhaps but being fat adapted means your brain is primarily burning ketones for fuel instead of glucose. Ketones burn cleaner in the brain with less reactive byproducts than glucose. Dementia eases when patients are fasted or given exogenous ketones. Being metabolically healthy and in a fasted state also means you're not distracted from dopamine snack cravings which many confuse with real hunger and I think has a worse effect on mood and cognition. In addiction your frontal lobe fights for control over your lizard brain. Addiction means your lizard brain is winning over self control.
Another perspective would be that when your body switches to survival mode due to adverse circumstances (such as cold or hunger), it mobilizes all its physical and cognitive resources. When the body is fighting for survival, it's about everything. This is probably the reason why many people report that they are capable of peak performance in this state. The body usually doesn't give more when it has more, but does the opposite. It saves and conserves its resources for worse times.
With intermittent (as in "eat one meal a day") fasting you can set your intake to align for when you need most brain work done.
Also, at least from my own experience, after some time you just get used to that and are hungry later and not as hard. When I eat around noon I only start getting hungry in the evening
I feel lethargic after eating. I find it hard to concentrate when hungry. I'm only productive in those 1-2 hours between the brain fog wearing off and the next hunger wave coming on.
I tried the meat diet for a few days (yes, I know that's too short! I couldn't get through the "keto flu") and I was blown away by how stable my mood and energy level was after having steak for breakfast. I wouldn't get hungry at all for the next 8-10 hours.
I tried multiple times 1-4 days around 25 - 23 years ago and
1. I didn't feel hunger and I don't think everyone needs to feel it
2. I focused a lot better,
I would probably do it a lot of I lived alone.
In practice I often end up with some kind of intermittent fasting: skip meals between 1700 and 1200 (lunch next day) and even then I happily minimize my lunch.
