Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

The power of intermittent fasting

bbc.co.uk

Post reply on HN
Print view View original

61–70 of 72 posts

Re: The power of intermittent fasting

#61

Post by Lost_BiomedE »

saljam wrote: post #36

In addition to fasting on the month of Ramadan, Muslims are “recommended” (i.e. it's considered virtuous but not obligatory) to fast on Mondays and Thursdays of every week. That sounds eerily similar to the 5:2 diet in the article. http://en.wikipedia.org/wiki/Sawm#Days_for_voluntary_fasting Muslims also know what's called prophet David's fasting, which is to fast every other day. However, considering that includes w…

A lot of the scientific interest in IF started with studying Muslims during Ramadan. I assume that is why it is similar.

Re: The power of intermittent fasting

#62

Post by johnthedebs »

pmjordan wrote: post #59
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,…

Thanks for posting this! I've had this problem for a while and was convinced I was hypoglycemic but when I measured my blood sugar level, even at the peak of the symptoms, it was always perfectly normal. I had the blood glucose meter (and paranoia) because my sister is diabetic and I was afraid I might be too. It's somehow very comforting to be able to put a label on this and to know that it's not uncommon and (presumably) not dangerous.

Re: The power of intermittent fasting

#63

Post by DanI-S »

pmjordan wrote: post #59
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 was always told that the thing that makes you irritable and cloudy-minded before eating breakfast in the morning is 'low blood sugar'. Sounds like it's probably just 'being hungry' :)

Re: The power of intermittent fasting

#64

Post by DaniFong »

reasonattlm wrote: post #54
DaniFong wrote: post #49

Earlier quoted context omitted.

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…

Where are you based? Would love to host you, Cynthia Kenyon, and my friend Laura Deming for a dinner on aging research.

Re: The power of intermittent fasting

#65

Post by jacques_chester »

backprojection wrote: post #43
jacques_chester wrote: post #32

Earlier quoted context omitted.

> 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 hypoth…

I have found myself arguing with people who took the view that the conservation of energy and matter does not apply to sufficiently complex biological systems.

I am quite serious.

Re: The power of intermittent fasting

#66

Post by jacques_chester »

randallsquared wrote: post #57
jacques_chester wrote: post #38

Earlier quoted context omitted.

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…

25% is for extreme outliers.

http://examine.com/faq/does-metabolism-vary-between-two-peop...

BMR varies mostly on body size. Taller, heavier people have a higher BMR because there's more of them to keep alive.

Re: The power of intermittent fasting

#67

Post by DaniFong »

DaniFong wrote: post #64
reasonattlm wrote: post #54

Earlier quoted context omitted.

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…

Where are you based? Would love to host you, Cynthia Kenyon, and my friend Laura Deming for a dinner on aging research.

We do weekly salons here: thesprouts.com

Re: The power of intermittent fasting

#68

Post by cup »

beagle3 wrote: post #50
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…

I'm fasting at the moment for Ramadan. It goes for 30 days and theres no eating or drinking from sunrise (5 ish) to sunset (6ish). Actually the fast includes a lot of other things besides food. If anyone has any direct questions I'd be happy to answer them.

Re: The power of intermittent fasting

#69

Post by beagle3 »

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…

> Cut calories enough, you will lose weight. Raise them enough, you will gain.

That's true in the useless tautological sense.

I've read a case study a few years ago about someone who has to eat something like 10,000 calories a day, because after some serious illness, their body only takes in 20% or so.

Paper is also carbohydrates - albeit not ones that our gut can process. Any statement about "caloric intake" is so hard to measure to make statements about "caloric balance" vague. They are useful as a "small signal"[1] approximation around common steady states (which are often 1000-3000/kcal a day, although that's not a good characterization).

However, when you go away to this state, this approximation breaks down and stops working. A model that would have predictive power in the "large signal" setting would have to take your entire biomass (10 times as many bacterial cells, although only 10% of body weight; 30% or so of solid excretions; facilitators of many processes), and nonlinear effects of insulin, ketosis, and others.

[1] http://en.wikipedia.org/wiki/Small-signal_model

Re: The power of intermittent fasting

#70

Post by xyzzyb »

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…

It's not the study you describe, but there's already a lot of research to support the thesis that eating fewer calories (and fewer calories alone) than your body burns leads to weight loss and better health: http://www.forbes.com/2009/05/22/low-calorie-diet-lifestyle-...
Post reply on HN