This archived forum used to be called 'Peatarian' (in reference to Ray Peat).

A Case for Intermittent Fasting

I found a study that makes a compelling case for intermittent fasting:

Mice that were fed a high-fat diet developed obesity, hyperinsulinemia, hepatic steatosis, and inflammation.

Mice that were fed the same high-fat diet, but were restricted to an 8-hour feeding window, did not develop these symptoms. These mice ate the same total calories of the same high-fat food as the former group, yet remained lean and healthy.

The authors of the study attribute the benefits of the time-restricted feeding to a strengthening of metabolic/circadian rhythms. If nothing else, this study casts serious doubts on the "calories in, calories out" model of dieting and fat loss.

The full text is available here:
asked Mar 15, 2015 by Kasra
Great find Kasra. Here are some more studies on that question (arguing both for and against reducing meal frequency):
^ good stuff

6 Answers

2 day starvation triples lactase activity in rats

I don't know if I'd support intermittent fasting, but I don't think constant eating of small meals is a desirable thing.
answered Mar 15, 2015 by lvysaur
Old school farmers woke up 5am then moved around (light exercise) for 1-2 hours before breaking the fast.

The wake up mechanism is mainly driven by a huge spike of cortisol which helps you go from sleep state to awaken state. It takes the body around 40-60 minutes to settle depending ofcourse on your state of health .
So a good rule would be to atleast wait 1-2 hours after you wake up before eating.

The benifit I think lies in being aware about the effects of morning cortisol and then see if you can play around it some days.
answered Mar 16, 2015 by -Alex
The function of cortisol awakening response is unknown but it has been suggested to link with a stress-related preparation in regard to the upcoming day by the hippocampus. One hypothesis is: "that the cortisol rise after awakening may accompany an activation of prospective memory representations at awakening enabling individual's orientation about the self in time and space as well as anticipation of demands of the upcoming day... it is tempting to speculate that for the CAR, anticipation of these upcoming demands may be essential in regulating the CAR magnitude for the particular day. The hippocampus is, besides its established role in long-term memory consolidation, involved in the formation of a cohesive construct and representation of the outside world within the central nervous system processing information about space, time and relationships of environmental cues. This puts the hippocampus in a pivotal position for the regulation of the CAR."

tl;dr: Don't fuck with your morning cortisol spike by eating right after you wake up, unless you want to lose the concept of the self in time and space.

Waiting 1 hour before having breakfast seems reasonable. Can't imagine anyone is actually hungry immediately after they wake up.
some days i am hungry right after i wake up, but usually not.  But i am always craving something sweet when i wake up no matter what day it is.
Doesn't the language in the first one lean more towards indicating the value of regular meals for maintaining the circadian rhythm? That's kinda how I read it. Not so much about the importance of not eating for 16 hours a day, or whatever.
answered Mar 15, 2015 by 4a552f55cbb9
Have you ever tried a high-fat, low-carb diet with an intermittent fasting window? It reduces subcutaneous bodyfat remarkably well, but if the fasting window is too long, the stress of the cortisol and insulinemic responses probably does a great deal of long term damage, including increasing hidden or visceral fat.

The question of how long your fasting window can be before your liver and tissue run out of stored glycogen really just depends on how healthy you (or the mice) are.

To help with this, I think Peat suggests having more of your protein at the end of your fasting window, and more of your fat and sugar at the beginning of it.

I also think Peat's made it clear that the morphogenic "wave-lengths" that interact with molecular cascades include circadian rhythms, so I don't think there's much to be surprised by here. Or am I missing something?

One thing I don't see is, do they say what kind of fat comprised the high-fat diet? In theory, had the high-fat diet consisted of fully hydrogenated coconut oil, I'm guessing that Peat would expect the mice would have been lean even on the ad libitum diet.
answered Mar 15, 2015 by visionofstrength
edited Mar 15, 2015 by visionofstrength
Thanks, sorry I didn't see it. If I recall from my days of ketogenic intermittent fasting, duck lard has the most PUFA, and pork and beef lard have less, and they all have more than (even non-hydrogenated) coconut oil.
"The actions of nerves can be considered anabolic, because during a stressful situation in which the catabolic hormones of adaption, e.g., cortisol, increase, the tissues of the functional system are protected, and while idle tissues may undergo autophagy or other form of involution, the needs of the active tissues are supplied with nutrients from their breakdown, allowing them to change and, when necessary, grow in size or complexity."

– Protective CO2 and aging

Not that he is referring specifically to fasting but goes to show he does not believe that stressors are necessarily detrimental.
answered Mar 18, 2015 by peatón
i find my body wanting intermittent fasts more lately - whereas 3 months ago, it wanted some kind of a meal every couple of hours.  as always, let the body dictate.
answered Mar 18, 2015 by Nicholas
To add to this, I think the mind can be seen as an extension of the body, used to probe into new, untested ideas.

I can't say that I viscerally feel the desire to fast, but the idea is interesting enough to me right now that I'll try it to see what effect it has.
Meh, my body dictated for over a couple years that skipping breakfast was not a big deal. I wasn't overcoming an instinct to eat. Then my health deteriorated.

I'm really not a big believer in the "follow your instincts and whims" school of thought. In most areas of life, not just diet, following wise rules is the best approach.

Sort of an interesting parallel to the Sola Scriptura approach vs. the catechisms. I'd say history bears out the idea that people who thought they could reason out things by first principles and instincts were usually very wrong. It's much better to doubt yourself and go with proven wisdom.
i don't really think of it as instincts so much as just being perceptive.  To artificially make myself eat 6 meals a day now just because i did three months ago is not being perceptive.  was merely trying to show that just because there may be value to intermittent fasting doesn't mean that now we should try to artificially implement it into our lives.  it has to come out of a natural place and need.  i believe the body really does dictate what to do if it can be perceived correctly - which is also part of the journey.  following one's instincts and whims doesn't have to be reckless a la Matt Stone but can actually be very grounded in real proven wisdom.  doubting yourself is part of the process of learning how to be perceptive....learning when the doubt is valid and when it is not.  staying inside of this perceptive state is the only thing that anyone can do that is truly productive and meaningful when it comes to well being.