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The power of intermittent fasting

bbc.co.uk

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Re: The power of intermittent fasting

#41

Post by anamax »

jacques_chester wrote: post #32
backprojection wrote: post #31

Earlier quoted context omitted.

>But do you know why? It isn't the schedule that really matters. You haven't shown that. Where's the randomized experiment where one group is assigned to eat 3000 cal/day evenly distributed, and the other group is assigned 6000 cal during an 8 hour window, every other day, and then the same thing but now 1800 cal per day, or 3600 every other day? I don't fully understand this compulsion to explain anything successful…

> I don't fully understand this compulsion to explain anything successful in the weight-loss field, ultimatlely, in terms of calorie restriction. Because any other hypothesis has to explain why it violates the conservation of energy and matter. (Also: such studies are harder than they look to arrange. Completely controlling someone's caloric intake and output is difficult to achieve). What tends to happen in discussi…

> > I don't fully understand this compulsion to explain anything successful in the weight-loss field, ultimatlely, in terms of calorie restriction.

> Because any other hypothesis has to explain why it violates the conservation of energy and matter.

Umm, no. None of the weight loss diets violate the conservation of energy and matter. (The "I lived on just water for 10 years" diets do.)

Feces contains calories. Therefore conservation of energy isn't the only limiting factor - conversion and usage matter too.

There's no "conservation" argument that says that conversion effectiveness is a constant. Heck, there's no argument that says that calories/pound is a constant.

> But the direct cause of weight loss in IF is that you simply do not eat as much.

Nope. You lose weight when your body "releases" more mass than you're taking in.

Re: The power of intermittent fasting

#42

Post by gwern »

BlackJack wrote: post #4

A big thing to stress here is that you eat normally the other days . I know some people who have tried IF who gorge on food once the fast ends, and end up no better off than not fasting at all - calorie wise at least.

That's good advice if you want to lose weight, but a number of IF studies were calorie neutral (double rations on non-fast days) and that's why I find it interesting: it's triggering some of the same benefits as CR but without restricting calories, which means it may be a much easier lifestyle to maintain.

Re: The power of intermittent fasting

#43

Post by backprojection »

jacques_chester wrote: post #32
backprojection wrote: post #31

Earlier quoted context omitted.

>But do you know why? It isn't the schedule that really matters. You haven't shown that. Where's the randomized experiment where one group is assigned to eat 3000 cal/day evenly distributed, and the other group is assigned 6000 cal during an 8 hour window, every other day, and then the same thing but now 1800 cal per day, or 3600 every other day? I don't fully understand this compulsion to explain anything successful…

> I don't fully understand this compulsion to explain anything successful in the weight-loss field, ultimatlely, in terms of calorie restriction. Because any other hypothesis has to explain why it violates the conservation of energy and matter. (Also: such studies are harder than they look to arrange. Completely controlling someone's caloric intake and output is difficult to achieve). What tends to happen in discussi…

> Because any other hypothesis has to explain why it violates the conservation of energy and matter.

This comment is so infuriating. I may not be a genius, but I did manage to eek out a degree in physics. I think I, and anyone here on HN should be given the benefit of the doubt that they can figurer out if energy conservation is being violated.

Simply from a principle of assuming that the person suggesting the hypothesis is not an _idiot_, you could infer that any of these alternative hypotheses do _not _ violate energy conservation.

Re: The power of intermittent fasting

#44

Post by dpn »

pakitan wrote: post #40

I see people here mostly talk about effects fasting has on health but not much about effects on mental/physical performance. If you live longer but you're less effective in what you do, fasting turns into a much less attractive choice, at least for some people. From my very non-scientific experiments, I can tell that my bullet (1 min) chess rating suffers a lot when I'm restricting my calories. It's really hard to me…

I tend to be a lot more productive when fasting.

I also tend to be more impulsive, so staying focused on the thing I should be doing, as opposed to what I want to do, is definitely an issue.

That being said, the time I save by not eating breakfast is also nice :)

Re: The power of intermittent fasting

#45

Post by dpn »

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 was like that when I started IF. I'm much better now. The biggest thing was reminding myself that I was crabby because of the food and I'd be able to eat soon enough.. that normally put me on the right track.

It's hardly an issue now, which I love.

Re: The power of intermittent fasting

#46

Post by dpn »

DenisM wrote: post #39
ams6110 wrote: post #29

Earlier quoted context omitted.

I think this is actually very likely to be true. Think about living as a hunter-gatherer. Some days you just won't find/catch anything. Maybe you snack on a few insects. Other days you bag an antelope or find a big patch of berries and you have more than you can eat. Alternating between fast and feast every few days seems like it would be quite common. Eating a regular 3 meals a day is probably not the norm.

So, two prehistoric men discuss cooking: - cooking meat should make you live longer - I don't know, man, my father always ate raw meat and he lived without any problems all the way till the old age of twenty one! My point being, just because it's the old way, doesn't mean it's the better way.

The obvious counter to that argument is that people didn't die of obesity, we didn't have antibiotics yet. :)

Re: The power of intermittent fasting

#47

Post by dpn »

stevenkovar wrote: post #21

Check out Martin Berkhan's http://leangains.com for more about making muscle gains while fasting. There's a subtle difference between using fasting as a tool for weight loss and one for body fat loss, but it's a difference nonetheless—it largely boils down to better management of your macro-nutrients (proteins, fats, carbohydrates) versus "eating like normal" after a fasting period. The most basic explanation is that…

I've been doing LG for over a year now. I swear by it!

Re: The power of intermittent fasting

#48

Post by dpn »

backprojection wrote: post #31
jacques_chester wrote: post #9

Intermittent fasting works for me: http://chester.id.au/2012/04/17/my-diet/ I love food. I love everything about it. I love the smell of it, the sight of it, the way steam rises of freshly cooked food. I love mixing it up. I love the act of chewing, the taste, the way it feels in my mouth. The act of swallowing is great and the sensation of fullness is sensational. So it should come as no surprise that for me , at le…

>But do you know why? It isn't the schedule that really matters. You haven't shown that. Where's the randomized experiment where one group is assigned to eat 3000 cal/day evenly distributed, and the other group is assigned 6000 cal during an 8 hour window, every other day, and then the same thing but now 1800 cal per day, or 3600 every other day? I don't fully understand this compulsion to explain anything successful…

Not exactly what you're asking for but there's a bunch of nice summaries with links to studies here: http://www.leangains.com/2011/06/is-late-night-eating-better...

Re: The power of intermittent fasting

#49

Post by DaniFong »

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.

Re: The power of intermittent fasting

#50

Post by beagle3 »

pgrote wrote: post #10

ADF is the unknown secret to solving many modern ills ... or so I think. :) I've had many conversations with three doctors about it and my thought is our bodies haven't caught up evolutionary wise to eating each and every day. I have no proof outside of personal results, which I understand doesn't make it a reality. I could be a freak. lol They key is not eating at all for a full 24 hours including your sleep cycle a…

> They key is not eating at all for a full 24 hours including your sleep cycle and then to only eat a normal meal on the days you eat.

I've gone on 7-21 day fasts, with good results and improved health. I agree with you, except I think the "24 hour" limit is rather arbitrary - up to 30 days yearly is common in some eastern religions with no irreversible damage (note - I'm not recommending everyone go on a 30 day fast; just that 24 hours is arbitrary, and the real limit is apparently some 30 times higher)

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