This was surprising to me because the advice I am hearing lately (time restricted eating, intermittent fasting) is to eat within a restricted time (ideally shorter than 12 hours).
So, at first glance I expected that the protocol here was to eat only while the sun is up, but it's actually the reverse.
It seems that the benefits of fasting outweigh the downsides of eating outside a restricted time window.
I guess it depends on where you live. Eight hours exceeds the time from dawn to sunset for much of the year in northern latitudes. Also, the study doesn't say 16:8 doesn't have the same effects.
> Fourteen healthy subjects fasted from dawn to sunset for over 14 h daily. Fasting duration was 30 consecutive days.
Edit:
There's an infographic further down that changes how I read this. Participants have a late dinner (after sunset) and an early breakfast (pre-sunrise), and fast for at least 14 hours while awake. Traditional IF counts time asleep as part of the fast, and this does not.
However, the pre-dawn breakfast essentially resets the fasting clock every morning, which means subjects have two fasting periods per day: about 8 hours while asleep, and about 14 hours while awake.
That leaves a two-hour eating window at night, and a short (let's call it thirty minutes) eating window in the morning.
This is closer to One Meal a Day (OMAD) than 16/8 in terms of hours spent fasting, but the pre-dawn feeding does make this a unique strategy.
>That leaves a two-hour eating window at night, and a short (let's call it thirty minutes) eating window in the morning.
Could this strategy match any kind of naturally-ocurring pre-historic behavior? It would make sense, at least to me, to constrict one's feeding window like that, since eating would take place for as little time as possible and would be limited to two and a half hours with no activity in between. And I'd guess any kind of activity during the day would need no interruption, as well as large energy reserves.
Some populations almost certainly ate like this at least some of the time, but it's dangerous to talk too specifically about "what life was like back then." There's just too much variation.
We know that periods of fasting are good for us; even setting this study aside, we know that autophagy is stimulated by fasting. This does tell us that our ancestors fasted often enough that our bodies are designed to benefit from it, but we can't draw more specific conclusions like "we should eat for eight hours a day" or "we should eat every other day."
Also, the fact that modern eating patterns cause disease (which is more or less undisputed) does not mean that our ancestors had a perfect plan that we should follow.
A researcher I know says it's because the publication date corresponds to the release date of the issue of the journal the article is being published in, though it's common articles are e-published ahead of the journal issue's publication date.
They enrolled people "in excellent general health" intending to observe Ramadan and did the fasting over Ramadan. I didn't read the whole study but I don't see the evidence that subjects had a disrupted circadian clock to beign with. It is certainly not a study of circadian disorders and as far as I know there is no evidence that adjusting eating affects sleep, however it makes sense that the timing of eating affects things related to energy and metabolism and that those relate to many of the issues with circadian disruption. I had not heard of proteomics before and don't know how well validated that analysis is or how these results compare to other methods of fasting.
I like the results of this study but I noticed n=14 so I'm not going to put too much weight on all the findings. Would be nice to see this replicated with other, equivalent fasting schedules.
Still, reading this makes me want to continue eating early dinner, drinking coffee black, and skipping breakfast experiment (which has a n=1 sample size). Even if there were not health benefits (which I'm sure there are), I like the mental clarity++ it brings.
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[ 3.6 ms ] story [ 66.9 ms ] thread* First human serum proteomics study of 30-day intermittent fasting from dawn to sunset in healthy subjects
* The 30-day intermittent fasting from dawn to sunset is associated with a serum proteome protective against cancer
* Intermittent fasting from dawn to sunset for 30 days upregulates proteins protective against obesity, diabetes, and metabolic syndrome
* Intermittent fasting from dawn to sunset for 30 days induces key regulatory proteins of DNA repair and immune system
* Intermittent fasting from dawn to sunset for 30 days upregulates proteins protective against Alzheimer’s disease and neuropsychiatric disorders
So, at first glance I expected that the protocol here was to eat only while the sun is up, but it's actually the reverse.
It seems that the benefits of fasting outweigh the downsides of eating outside a restricted time window.
Not eating all day long is tough; it's a lot easier when you get to count your sleep time as fasting. :)
> Fourteen healthy subjects fasted from dawn to sunset for over 14 h daily. Fasting duration was 30 consecutive days.
Edit:
There's an infographic further down that changes how I read this. Participants have a late dinner (after sunset) and an early breakfast (pre-sunrise), and fast for at least 14 hours while awake. Traditional IF counts time asleep as part of the fast, and this does not.
However, the pre-dawn breakfast essentially resets the fasting clock every morning, which means subjects have two fasting periods per day: about 8 hours while asleep, and about 14 hours while awake.
That leaves a two-hour eating window at night, and a short (let's call it thirty minutes) eating window in the morning.
This is closer to One Meal a Day (OMAD) than 16/8 in terms of hours spent fasting, but the pre-dawn feeding does make this a unique strategy.
Could this strategy match any kind of naturally-ocurring pre-historic behavior? It would make sense, at least to me, to constrict one's feeding window like that, since eating would take place for as little time as possible and would be limited to two and a half hours with no activity in between. And I'd guess any kind of activity during the day would need no interruption, as well as large energy reserves.
We know that periods of fasting are good for us; even setting this study aside, we know that autophagy is stimulated by fasting. This does tell us that our ancestors fasted often enough that our bodies are designed to benefit from it, but we can't draw more specific conclusions like "we should eat for eight hours a day" or "we should eat every other day."
Also, the fact that modern eating patterns cause disease (which is more or less undisputed) does not mean that our ancestors had a perfect plan that we should follow.
So they didn't even drink water?
I never liked eating, it's a hassle and you get used to not eating during the day, especially if you get zoned into work.
How much did these people eat daily before their 30 day fasting experiment? Could this just be due to not over consuming calories on the regular?
Did they eat the same amount and same foods but instead confined to their new fasting times?
There are so many variables that were changed in this study that it is hard to pinpoint that one of them is the true reason for their adaptation
Still, reading this makes me want to continue eating early dinner, drinking coffee black, and skipping breakfast experiment (which has a n=1 sample size). Even if there were not health benefits (which I'm sure there are), I like the mental clarity++ it brings.