[distantaidenn]

I'm a daily faster for the past 20 years, so I can attest (anecdotally) to the benefits of working while hungry. Once you adapt, after a couple weeks, instead of being irritable when hungry, you mind feels clear and focused. After all, despite the trappings of modern society, we are a predator species. Hunger gets shit done.

When I was a kid, I recall the teachers always telling us to have a good meal before a test. Even then I felt that was silly, as a big lunch always gave me brain fog.

Anyway, I'm surprised this article (study?) didn't take into account "meeting fatigue". I know that for myself, after an hour in a meeting, I just want to get out so I can recharge. I know nothing productive will happen until I do so.

[PurpleRamen]

> instead of being irritable when hungry, you mind feels clear and focused.

From my experience, it's a delusion. The focus is there for some while, but the actual abilities decline very fast without you even realizing it because of this supposed clearness. It might be even that the clearness comes exactly because of your mind limiting itself to a shorter attention and horizon, removing all the complex and complicated things. It's basically being in the zone, but the zone itself is so limited that you might not do good work if you need to have a "big zone". Though, it depends on your type of work if this can be beneficial. But as a knowledge worker, I consider it harmful for my work.

> When I was a kid, I recall the teachers always telling us to have a good meal before a test. Even then I felt that was silly, as a big lunch always gave me brain fog.

Depend on the type of food, size of meal and how long before the test you were eating.

[throwaway290]

From my experience, I think clearest when my body is not busy digesting.

Just as you say my experience is a delusion I can suggest that perhaps your feeling of expanded attention and horizon could be a fallacy caused by your attention in fact becoming more limited as your body diverts blood (and so oxygen) from your brain to your stomach and gut for food processing (which takes hours, so if you eat 3 meals this is basically your entire day).

[distantaidenn]

I can't agree with it being a delusion. Again, my personal experience is just that -- personal.

Ketones are associated with fasted states and/or restricted carbohydrates. The average person holds about 400-500g of glucose (1600-2000 calories) in their bodies. Once that is depleted, through fasting or carb restriction, you will switch to ketogenesis to provide fuel. There are numerous studies that show a positive correlation with ketone production and cognitive performance.

Few examples: > https://pubmed.ncbi.nlm.nih.gov/25404320/ > https://pubmed.ncbi.nlm.nih.gov/27528626/

If I am doing serious deep work, I can go 8 to 10 or so hours without even thinking about food. However, once I do eat, I'm done with any serious work for a few hours. Keep in mind, I'm operating from a 20 year experience of intermittent fasting (before it was cool).

To reiterate, I don't think it's a delusion. We evolved in a feast or famine state. Dense carbohydrate sources and constant satiation were rare when our base metabolic pathways evolved.

[andirk]

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?

[throw10920]

> From my experience, it's a delusion.

You say this, implying that you got some objective outside measurement to confirm you were being deluded - what was it?

[ilyt]

Not my experience. I eat one meal a day and I don't really get work going before that meal (which is usually around noon).

It's not even that I feel particularly hungry (unless I ate less than usual yesterday), peak of hunger is usually somewhere before I go asleep, I just feel a bit lethargic.

I only get "brain fog" some time after eating a lot of sweet or otherwise easily accessible sugars

> Anyway, I'm surprised this article (study?) didn't take into account "meeting fatigue". I know that for myself, after an hour in a meeting, I just want to get out so I can recharge. I know nothing productive will happen until I do so.

I swear I feel way more drained after a day of meetings than a day of brain work...

[katbyte]

In uni I would always have an energy drink during my tests, sugar is pure calories and fuel so doesn’t cause food fog

[distantaidenn]

> Not my experience. I eat one meal a day and I don't really get work going before that meal (which is usually around noon).

Of course, you do what is best for you. But I recommend you do some research in the parasympathetic and sympathetic nervous systems and how these systems relate to fasting and energy expenditure/utilization based on the diurnal cycle.

For my IF schedule, I aim to maximize the efficiency of both. This results in my having only an evening meal. I.e. active and responsive during the day (fasting), relaxed and digesting during the evening (meal time) before sleep.

[lr4444lr]

I did this in college, and I had super focus during my morning classes, but after my first meal of the day at 11:30 or noon, I needed something like a 2 hour nap, and I definitely didn't recover the initial fasted performance level until the following morning. I don't deny fasting works better for some or many, but it depends what you're optimizing for. I prefer the steady energy of 3 meals a day spaced out 5-7 hours, all 3 macronutrients in each. Also, in trying to put on muscle as a rail thin person, there's no way I can imagine doing any fewer meals per day.

[toast0]

> When I was a kid, I recall the teachers always telling us to have a good meal before a test. Even then I felt that was silly, as a big lunch always gave me brain fog.

Insufficient direction from the teachers there, I think. A good meal in this context doesn't mean a big meal, usually. You'd want to eat like you were planning to do some strenuous exercise shortly afterward. If you eat big and then go running, that's no good; if you have a roughly typical diet, you want a mix of carbs, fat, and protein, as those provide energy on different timescales. If you keep a diet which avoids one of those things, you do you, but you still want the same goal of energy available over time, not eating too much that digestion needs overwhelm everything else, nor not little that hunger distracts.

[raverbashing]

> Hunger gets shit done

Hunger gets something done. Not necessarily the right thing. I see what you mean though

> always telling us to have a good meal before a test

I wonder how many of these are 'outdated memes' from times where kids were more neglected and/or didn't have supervision then went to school however and 'eat a good meal before a test' actually means 'try to eat something before coming to school one time this week'

[hgsgm]

Hungry schoolchildren are not an "outdated meme" . North Dakota legislature just voted to take food from schoolchildren and give it to themselves.

[thunderbong]

Totally agree. The amount of clarity I get in my thinking when I fast is at a different level.