When you do not eat, you are not permanently hungry, at least not when you are accustomed to this. This is similarly like when you feel that you must immediately use the restroom, but when that not happens the sensation disappears and it may come back only one hour or two later.
What is funny is that, at least for me, the sensation of hunger is strongly conditioned by whether there really exists a possibility to satisfy it.
I eat 2 meals per day and during the time between them I am not hungry, and if I were hungry that would be futile, because I intentionally do not keep in my home any kind of food that can be eaten instantly, but only raw ingredients that I must cook before eating.
After I cook my next meal, I have to be patient and wait some time for the food to cool down. During that time, I become suddenly very hungry and like you say, I find it difficult to continue to work at the computer or at whatever I was doing, as my thought shifts to the food I am waiting to eat.
In the past, when I kept food that could be eaten at any time, without preparation, I became frequently hungry and it was hard to resist to the temptation of having a snack.
Some people never seem to be able to think clearly or focus while fasting, independently of any feelings of hunger. There is likely some biological variability here, but it could also be due to metabolic problems that are making it hard to provide the brain with energy during a fast. In some cases the fasting itself can help treat that, and it may get better over time.
People respond differently to fasting, some are never able to do focused knowledge work during a fast, others can’t at first but can once their bodies get used to fasting. Others can immediately focus better right from the beginning. There is a lot of individual variation.
I literally cannot sleep if hungry. I wake up in the middle of the night if I had dinner and went to bed at midnight.
My trick is to eat one apple right before sleep, then I wake up not hungry and can sleep well.
I did that before, my breath becomes horrible when that happens, but it's way more manageable.
Is there a way to activate ketosis before starting the fasting? That seems like it could solve my problem
Ketosis is your body using fat as an energy source when glucose isn't readily available. So if you deprive yourself of dietary glucose (carbs, simple sugars, etc), but keep eating fat and protein, you'll enter ketosis while eating as much sustenance as you want. Use ketone strips to tell when it happens.
Apologies in advance for the pedantic response, but the human body can generally make enough glucose from protein to keep you out of ketosis. You usually have to restrict both protein and fat to reliably induce ketosis. You can confirm this for yourself with ketone test strips. Most dieters on so called ketogenic diets are not actually in ketosis.
Even more surprising is that fermentable fibers get converted into short chain fats by bacteria in the gut that are ultimately metabolized as ketones, so a diet high in those can induce ketosis even with a high carb diet. Some herbivore animals are always in ketosis, and some carnivores are almost never in ketosis unless they are starving and can’t find protein.
I believe you but can't attest from personal experience. Almost any time I've gone low carb and into ketosis, I've also reduced my calorie intake. All you can eat bacon and eggs gets old quick.
