The power of intermittent fasting • Hacker News Board

Re: The power of intermittent fasting

#51

Post by beagle3 » Sun, Aug 05, 2012, 8:38 PM UTC

latch wrote: post #6

I've started to fast for a 24 hour period once a week (lunch on monday is my last meal until lunch on tuesday). I drink tea and water. I'll break my fast early if I have any signs of feeling unwell. I haven't noticed any changes, but I was already in good shape, slept well, and what not. I'm not sure I buy the health benefits for people who are already healthy. I tend to favor going by what the experts say, and overw…

> I tend to favor going by what the experts say, and overwhelmingly they say to eat normally every day. The more progressive might admit that there's value in further study.

I tend to follow experts when I don't have time to do my own research. But when I do, I find -- very often, with nutrition advice, and too often for comfort with medical advice -- that there's actually no scientific basis for these recommendations; rather that they are somewhere between "leap of faith" (that is sometimes provably wrong), superstition, and "that's the way we've been doing for a while so we assume it's the right way".

For example, many experts still insist that you should limit egg yolk consumption to no more than a few a week, although there's no science behind it - just a 60 year hypothesis that's been repeatedly disproved over the last 30 years (although the belief is so strong almost no one seems to be aware of those results).

And many still insist that the more cushioning for your ankle on your shoe the better - although there was never any research indicating that this should be true, and there is very consistent evidence showing that it is in fact harmful.

> On a different note... A couple years ago (long before I started fasting), I was in a meeting and I got super hungry. It was painful. I realized that many people live with this daily for decades. I think going hungry for a short period of time might make some people more empathetic.

I had fasted for 21 days once, and did not feel any discomfort throughout (on the contrary - up until day 14 or so, I felt disgusted at the thought of food; after that, it just wasn't appealing). And then I felt hunger. Which is something completely different from appetite, which is what I referred to as hunger before.

hunger is something that I've only ever felt at the end of the fast, and at the end of an army training camp that didn't provide enough food -- and I assume most people in the western world never do (although you might have - I can't really tell).

It's not pain. It's an obsession with food that will not go away when you do something interesting, which is unlike food craving or appetite - but I can't really put it into words.

Re: The power of intermittent fasting

#52

Post by beagle3 » Sun, Aug 05, 2012, 8:40 PM UTC

Swizec wrote: post #12

sandGorgon wrote: post #11

The article is not very clear behind the science of intermittent fasting - for those who are interested, do definitely read Alan Aragon's article [1] as well as /r/advancedfitness. My personal view is that meal frequency is irrelevant for body biochemistry. What is happening is CNS (central nervous sytem) Adaptation - you are, for the first time, truly understanding how really hungry you are. Your body begins to unde…

I would wager this depends a lot on the type of activity you're doing. Sometimes after a really hard boxing practice I can be so hungry that I physically can't eat any more food, but I'm still hungry. And no, it isn't just a bug in the brain, the calorie tracker also agrees that I haven't eaten enough.

> Sometimes after a really hard boxing practice I can be so hungry that I physically can't eat any more food, but I'm still hungry.

For me it is the complete opposite - I can't eat or even think of food for a while, and am definitely not hungry or have any appetite -- and the harder the practice is, the longer it takes appetite to recover. (My practice of choice is thai boxing, btw...)

Re: The power of intermittent fasting

#53

Post by mgcross » Sun, Aug 05, 2012, 9:13 PM UTC

I've got a friend who has been on something akin to the warrior diet without knowing it. He works as a server, so He's up all night and sleeps during the day with one grand, large meal he eats in the afternoon. He did it more as a convenience than anything, but has lost about 20lbs in the past few months. I normally eat every few hours, but may try this out as long as it doesn't adversely impact my work or exercise regime.

Re: The power of intermittent fasting

#54

Post by reasonattlm » Sun, Aug 05, 2012, 9:14 PM UTC

DaniFong wrote: post #49

reasonattlm wrote: post #22

The interesting thing about intermittent fasting is that it seems to work through a different but overlapping set of molecular mechanisms to calorie restriction. The gene expression profiles in rodents say that the way in which intermittent fasting (such as alternate day fasting, the most commonly studied mode) works to alter metabolism into a better running state is not quite the same as the mechanisms of straight c…

Great point; I've been thinking about this for some time. Would love to have more data, though! I'm also interested in any metabolic similarity either influence has to endurance athletics.

Exercise and calorie restriction both influence autophagy. In fact pretty much everything that extends life in laboratory animals boosts autophagy one way or another - such as through altered expression levels of heat shock proteins and related regulators. You'll find that foundational study on exercise mimetic drugs looks at heat shock protein manipulation more often than not.

http://www.fightaging.org/archives/2012/01/testing-autophagy...

http://www.fightaging.org/archives/2009/09/heat-shock-protei...

http://www.fightaging.org/archives/2008/03/all-roads-lead-to...

There is no consensus on whether different types of aerobic exercise are better or worse for longevity, or whether more than the modest 30 minutes a day is better or worse for longevity. Elite athletes have a massive longevity advantage over the rest of the population, for example, but that can just as well be explained by the fact that you have to be robust to become an elite athlete in the first place.

http://www.fightaging.org/archives/2011/05/putting-upper-bou...

Exercise also works through hormesis and reactive oxygen species signaling - which is why flooding your system with ingested antioxidants can destroy some of its benefits:

http://www.fightaging.org/archives/2009/05/exercise-reactive...

Re: The power of intermittent fasting

#55

Post by mgcross » Sun, Aug 05, 2012, 9:15 PM UTC

DanI-S wrote: post #25

Am I the only person who becomes extremely irritable once their blood sugar gets low? I can't imagine fasting for a day - I'd have no friends left by the end of it.

I get the same way from time to time, especially after a workout. I feel (but could very well be wrong) that it's a sign of insulin resistance.

Re: The power of intermittent fasting

#56

Post by Swizec » Sun, Aug 05, 2012, 9:15 PM UTC

beagle3 wrote: post #52

Swizec wrote: post #12

Earlier quoted context omitted.

I would wager this depends a lot on the type of activity you're doing. Sometimes after a really hard boxing practice I can be so hungry that I physically can't eat any more food, but I'm still hungry. And no, it isn't just a bug in the brain, the calorie tracker also agrees that I haven't eaten enough.

> Sometimes after a really hard boxing practice I can be so hungry that I physically can't eat any more food, but I'm still hungry. For me it is the complete opposite - I can't eat or even think of food for a while, and am definitely not hungry or have any appetite -- and the harder the practice is, the longer it takes appetite to recover. (My practice of choice is thai boxing, btw...)

This is usually an hour after practice. Takes a while to get home, take a shower, prepare the food etc.

Re: The power of intermittent fasting

#57

Post by randallsquared » Sun, Aug 05, 2012, 9:16 PM UTC

jacques_chester wrote: post #38

randallsquared wrote: post #34

Earlier quoted context omitted.

The relationship won't be linear, immediate, proportional or unary. But it will be causal. So... you agree with the comment you're replying to, then? No one disputes that a body cannot burn more energy than it has taken in. However, other factors can swamp a "mere" 25% percent reduction in caloric intake. IF has been the most effective weight loss strategy for me, but it doesn't work forever unless you keep reducing…

One thing you probably overlooked: fat cells add to BMR.

While I didn't overlook it entirely, it's true that it is quite difficult to know how to account for it without , since resting metabolism varies widely ( http://en.wikipedia.org/wiki/Basal_metabolic_rate#Causes_of_... suggests more than 25% variation after accounting for a number of potential factors). My own anecdotes suggest that once the (my) body adapts to higher caloric intake, it discards much more of it than when times are leaner.

Re: The power of intermittent fasting

#58

Post by mgcross » Sun, Aug 05, 2012, 9:23 PM UTC

beagle3 wrote: post #51

latch wrote: post #6

I've started to fast for a 24 hour period once a week (lunch on monday is my last meal until lunch on tuesday). I drink tea and water. I'll break my fast early if I have any signs of feeling unwell. I haven't noticed any changes, but I was already in good shape, slept well, and what not. I'm not sure I buy the health benefits for people who are already healthy. I tend to favor going by what the experts say, and overw…

> I tend to favor going by what the experts say, and overwhelmingly they say to eat normally every day. The more progressive might admit that there's value in further study. I tend to follow experts when I don't have time to do my own research. But when I do, I find -- very often, with nutrition advice, and too often for comfort with medical advice -- that there's actually no scientific basis for these recommendation…

Just a personal aside on the egg yolks - When I was 20lbs overweight, my cholesterol was a little above 200. I've since lost weight and eat 4 whole eggs for breakfast, and my cholesterol stays around 130, unfasted. I'm careful when it comes to simple carbs but don't avoid red meat as much as I should, given my genetics.

Re: The power of intermittent fasting

#59

Post by pmjordan » Sun, Aug 05, 2012, 9:34 PM UTC

DanI-S wrote: post #25

Am I the only person who becomes extremely irritable once their blood sugar gets low? I can't imagine fasting for a day - I'd have no friends left by the end of it.

Are you sure your blood sugar level really is low (hypoglycaemia), that is, have you had it measured? Idiopathic postprandial syndrome is apparently much more common, presents similar symptoms except blood glucose levels aren't actually especially low and unlike hypoglycaemia, it does not appear to be dangerous (unless you're driving and it interferes with your concentration).

If you suffer from actual hypoglycaemia, I would not recommend leaving it untreated.

In the case of idiopathic postprandial syndrome, episodes seem to be brought on by the steep decline back to normal blood sugar levels, as opposed to actual lack of glucose. What this means is you can avoid the problem by not consuming sugary food and drink in the first place, or combining them with other, non-sugary foods. Basically, don't let your glucose levels get so high in the first place. Fasting for a day shouldn't bring on an episode (although you'll certainly be very hungry!) - eating sugary foods, then fasting, will, however.

Of course, YMMV and I'm not a doctor or even a nutritionist.

Re: The power of intermittent fasting

#60

Post by Supermighty » Sun, Aug 05, 2012, 10:42 PM UTC

I saw that other article about fasting and decided to give it a try yesterday. I made it about six hours before I realized my concentration was way off and my emotional balance was out of whack.

Granted I was also working a freelance job. Which in retrospective was probably a bad idea. However I did learn something about myself. And next time I try fasting I'll make sure that I don't have anything pressing due the same day.