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 calorie restriction.<p><a href="http://www.fightaging.org/archives/2010/05/intermittent-fasting-with-or-without-calorie-restriction.php" rel="nofollow">http://www.fightaging.org/archives/2010/05/intermittent-fast...</a><p><a href="http://www.fightaging.org/archives/2009/11/a-little-intermittent-fasting-research.php" rel="nofollow">http://www.fightaging.org/archives/2009/11/a-little-intermit...</a><p>So evidently you still have upregulated autophagy (i.e. better housekeeping in cells), the levels of methionine in the diet are going to be lower thus triggering that important switch in the metabolism of calorie restriction, more ghrelin floating around to stimulate the immune system, and so on. But it's not running the same way as for a steady low diet, and that appears to make some differences. Intermittent fasting is not as well studied as calorie restriction, but it is shown to extend life in mammals, and it is certainly easier to manage for most humans:<p><a href="http://www.fightaging.org/archives/2009/02/practicing-intermittent-fasting-versus-calorie-restriction.php" rel="nofollow">http://www.fightaging.org/archives/2009/02/practicing-interm...</a><p>Which means to say that you'll probably obtain health benefits by doing it, but the studies that show massive health gains and enormously lowered risk of age-related disease for calorie restricted humans may or may not apply to you.
Intermittent fasting works for me: <a href="http://chester.id.au/2012/04/17/my-diet/" rel="nofollow">http://chester.id.au/2012/04/17/my-diet/</a><p>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.<p>So it should come as no surprise that for <i>me</i>, at least, weight control through portion control has been an absolute failure.<p>What has worked for me is skipping meals altogether. If I don't start eating at a given meal time I don't have to stop.<p>These days I skip breakfast, have a simple meal-replacement of my own recipe at lunch, train in the afternoon and eat whatever I feel like at dinner. So far I am 24kg (~53lb) down from my peak weight and the trendline is still pointing down.<p>(I wrote about that, too: <a href="http://chester.id.au/2012/05/26/fat-and-simple/" rel="nofollow">http://chester.id.au/2012/05/26/fat-and-simple/</a> -- it caused one hell of a ruckus)<p>But do you know why? It isn't the schedule that really matters. It's that I imposed a caloric deficit in a way that I personally am I able to sustain. For others it might be low-carb or eating every 4 hours or being a vegetarian. Whatever. At the end of the forcing function of weight control is how much you ate.<p>Once I reach a weight I'm happy with I'll probably just eat an ordinary lunch more often.
Check out Martin Berkhan's <a href="http://leangains.com" rel="nofollow">http://leangains.com</a> 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.<p>The most basic explanation is that you can fast whichever periods you would like (most do 16 hour fasts + 8 hour "feeding windows"), but you must:<p><pre><code> A) Lift weights no more than 3 days a week
B) Lift heavy weights to stimulate muscle growth
C) Eat more carbs / less fats on workout days (more calories)
D) Eat more fats / less carbs on "rest" days (less calories)
</code></pre>
Compared to most lifestyles (this isn't a diet) this takes a lot of mental preparation and calculation, so it is more daunting initially and less mentally draining as you go on and see results (as compared to a fad diet which is simple to implement but impossible to maintain). It's not easy but, once a routine is established and the learning curve is overcome, many people make the decision to keep the 'LeanGains' lifestyle for the remainder of their lives.
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. <a href="http://en.wikipedia.org/wiki/Sawm#Days_for_voluntary_fasting" rel="nofollow">http://en.wikipedia.org/wiki/Sawm#Days_for_voluntary_fasting</a><p>Muslims also know what's called prophet David's fasting, which is to fast every other day. However, considering that includes water, it's considerably difficult to maintain. I'm not sure I heard of anyone other than David himself do it for a long period of time! <a href="http://en.wikipedia.org/wiki/Islamic_view_of_David" rel="nofollow">http://en.wikipedia.org/wiki/Islamic_view_of_David</a>
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'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.<p>I haven't noticed any changes, but I was already in good shape, slept well, and what not.<p>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 overwhelmingly they say to eat normally every day. The more progressive might admit that there's value in further study.<p>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.
It took me long enough to get used to eating every 3 to 4 hours. Now <i>this</i>?<p>Come on nutritionists, where was this theory when I was in high school and would randomly go for two days without eating ...<p>PS: eating every 3 to 4 hours has brought the biggest gains to my leanness of everything I've tried. Even better than running every day.
I've also been doing this for awhile now. The program I'm on is called LeanGains <a href="http://www.leangains.com/" rel="nofollow">http://www.leangains.com/</a> and I've been pretty successful with it. I've went from about 15% BF to 10% with minimal muscle loss.
ADF is the unknown secret to solving many modern ills ... or so I think. :)<p>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.<p>I have no proof outside of personal results, which I understand doesn't make it a reality. I could be a freak. lol<p>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.
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.<p>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 <i>really</i> hungry you are. Your body begins to understand that it does NOT need to eat breakfast, or eat something every 4 hours or eat a dozen nachos as an evening snack. When this happens, you automatically balance out on calories in vs calories out and you start losing weight.<p>I think this is a workaround for a bug in our brain - it makes pessimistic predictions for food availability and hunger responses.<p>[1] <a href="http://www.alanaragon.com/an-objective-look-at-intermittent-fasting.html" rel="nofollow">http://www.alanaragon.com/an-objective-look-at-intermittent-...</a>
This advice is sort of along the same lines as the Warrior Diet which preaches fasting all day and preserving yourself for one large prepared meal to quench your warrior instinct. I follow the Warrior Diet 3-5 days/week. It recommends eating vegetables during the fast (some lean proteins if you workout a lot) and also ways to start your one big meal. The diet plan instructs you to eat some vegetables first followed by protein and then grain.<p>I really like this diet, but it is difficult to follow everyday. I would say I have 2 cheat days/week where I eat a lot of junk food. This summer ice cream has been my haven. All in all I am down 40lbs since the beginning of this year... Should mention and thank the slow carb diet for at least 30 of those lbs... (note:slow carb diet is eating every 4 hours....)
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.<p>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 measure how fasting would affect a more complex activity, like programming...probably the impact is smaller but there certainly is an impact. With restricted calories, I usually need to add caffeine to the mix to suppress my hunger and make it easier to concentrate.
Here you can rate if those "fasting" methods/lifehacks works or not: <a href="https://didthis-actionwiki.appspot.com/tag/fasting" rel="nofollow">https://didthis-actionwiki.appspot.com/tag/fasting</a><p>To create new ones: <a href="https://didthis-actionwiki.appspot.com/create" rel="nofollow">https://didthis-actionwiki.appspot.com/create</a>, or fork those already in eg. <a href="https://didthis-actionwiki.appspot.com/intermittent%20fasting/copy" rel="nofollow">https://didthis-actionwiki.appspot.com/intermittent%20fastin...</a> (just add "/copy" at the end of the action link).
I've practiced inttermittent fasting for a bit (eating absolutely nothing with calories one day a week), and, apart from losing weight (which I can't attribute entirely to IF, since I was also eating less in general, but IF definitely helped), it was just more convenient for me.<p>I prefer to just eat nothing one day, which is relatively easy since I work/do stuff during the day and have to take time out of the day to eat, and then indulge the rest of the week. IF enabled me both to not keep in mind how much I eat six days out of the week, and to just simply not eat anything for one day. I consider it a great success.
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.
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.<p>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.
A big thing to stress here is that you <i>eat normally the other days</i>. 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.
Fast too much and your body goes into famine mode, where your fat storage management system is convinced that this month's food catch is low, and it is likely this will be a lean year. Therefore store everything you can to fat and keep energy outputs low. Causing obesity.<p>When I was 26 ish, i fasted for 3 days. I'm 30 now. Dumbest thing i ever did. I gained weight from that DAY I started eating again forward, and it's been a battle of the buldge ever since.