Intermittent fasting for active people?

5.Seven-Kevin wrote:

Your theory for this is that you're trying to eat in the time frame we "think" cavemen ate.

Truth is, we're  MUCH closer related to nomadic humans than cavemen, we started wandering around thousands of years ago and didn't recently start settling down until agriculture took off. Those nomadic humans would eat 6+ times a day, foraging on what they found and little animal product.

Stop trying to live like a species of homosapiens that did NOT thrive.

Maybe - or not. Largely depends to which period specifically we are referring to. I have a bit of a hard time believing that the cro magnon necessarily hate 6 times a day. A successfull hunt may take days/weeks. There may or not be stuff on any given day they could forage, it may or not be enough to matter or maybe not everyone got to have some when it was scarce. They probably didn't much ways of conserving food for long periods, and they certainly didn't herd animals yet (which is what nomadic people nowadays mostly do). Seems to me that some periods of fasting may have been on the schedule, at least from time to time.

At any rate, I think the "that's what caveman did" argument is somewhat marginal and not really why you would go into IF or not - it's more about (perceived or real) benefits...

Also, I'm not sure the argument about following caveman eating habits (or somewhat reproduce them) is about whether or not they thrived. I think it's more that we did that for millenias and such a long legacy probably didn't get erased yet by our relatively short period of success with towns, animal husbandry, fridges and iPads. Or in other words, we've been hardwired into doing things in a certain way the slow process of evolution and natural selection, but now that our evolution in terms of lifestyle changes at a speed that is completely out of whack with that of "normal" evolution and natural selection, we may do things that are actually counter-productive, from a biological perspective. Not saying I'm convinced or not by the argument, but there it is...

bttrrtRock wrote:

Good point Kevin but saying cavemen didn't thrive is a stretch. They out competed everything right? Otherwise would we be here? Anyhow, eating is a hassle. If I can train myself into eating less often and there are some added bonuses and few drawbacks - I'm sold.

Yeah - but then there were definitely rough patches, too. I think in Europe during the last ice age they got down to a couple thousands humans ancestors. So not exactly thriving.

Franck Vee wrote:

At any rate, I think the "that's what caveman did" argument is somewhat marginal and not really why you would go into IF or not - it's more about (perceived or real) benefits...

That's a very Islamophobic statement.

(jk obv. A large number of peer reviewed studies of Ramadan fasters have concluded that there are benefits to IF)

F

I thought this was an interesting and relevant article to this discussion: http://www.climbingnutrition.com/diet/intermittent-fasting-good-fit-climbing/

I thought I would point out what the article says regarding caloric restriction leading to longer lifetimes being some kind of scientific fact:

Scientifically, “caloric restriction” or “dietary restriction” tends not to mean a low calorie intake, but rather exactly what the words imply: restricted calories. In animal trials, this means that the “restricted calorie” group is not fed ad libitum, or given free access to food at all times. Instead, it means the scientists performing the study limit their calories, but almost always only to the amount that the animals maintain a healthy weight for their species and sex.

You can see this definition in action in a study on Rhesus monkeys widely cited by proponents of caloric restriction. One group of monkeys was essentially given a never-ending bowl of monkey chow whereas the other group had calories “restricted” to a normal amount for an adult Rhesus monkey.

What this means is that what the studies define as “caloric restriction” doesn’t match up with what you, or I, or any other person would think of caloric restriction, which is the purposeful restriction of calories to below a normal level. Indeed, in the studies that have demonstrated caloric restriction to be healthy, it would be more accurate to say that eating a “weight maintenance diet” is healthy whereas eating too many calories and gaining weight isn’t. This isn’t exactly a revelation!

Luna Luna wrote: based on the most current medical literature (which is constantly changing.. so as stated previously  there is plenty info on pubmed go ahead and read it for yourself)  genetically men are more likely to benefit from intermittent fasting than women.  Due to our different base hormone levels, humans with high testosterone and low estrogen levels can thrive on a model of intermittent fasting: gaining muscle and strength, while high relative levels of estrogen in the body cause a different reaction to starvation, even at short intervals.  estrogen causes a fat increase reaction, along with a handful of other side effects often regarded as negative.

This is a male dominated discussion. Have you read "roar"? I just bought it and I'm looking forward to what she has to say. What sites have you read that backs up this info? I was considering trying IM but will be relieved if I shouldn't because it'll work against me 

Lisa Haze wrote:

This is a male dominated discussion. Have you read "roar"? I just bought it and I'm looking forward to what she has to say. What sites have you read that backs up this info? I was considering trying IM but will be relieved if I shouldn't because it'll work against me 

FWIW, the little research I have done into IF suggests that there is no increased testosterone response until the HGH shows up several days into the fast (HGH and testosterone are highly correlated), and the HGH spike is likely one of the ways the body preserves itself by dis-promoting your body consuming muscle tissue for calories.  So yes, IF will increase your testosterone and HGH, but your gut and body will be so short of nutrient (this is what caused the spike in HGH and testosterone, so there is no workaround i.e. no way to have the hormone spike without the nutrient dificiency) that the spike won't make a meaningful difference because there is no material to build your body with.  Instead, your body will simultaneously reduce it's metabolism in order to maintain structure on the restricted calorie diet with the overall result being the body wanting to consume fat in favor of muscle, just at a way reduced metabolic rate compared to what you are likely going for. 

 A better bet would be to find a diet which more closely matches your metabolic rate (as in carbs vs. protien vs. fat), eat frequent but small meals to get your calories, and don't overdo it.  Most people struggling with diet/weight/metabolism overdo it on the carbs (which have the fastest rate of energy delivery) which requires that their body store the unused calories.  Then, since the energy came on too quickly from the carbs, their metabolism has to slow down to be able to get by on the available energy it did get from the carbs which it did not store.  this causes a negative feedback loop of more fat storage and a slower metabolism combined with a constant feeling of hunger.  I contend this is the reason low carb diets are so successful for so many people.  The best workaround to this is to feed the body calories that it does not have to store (so more fats and protiens), that way you can maintain or even increase your metabolism via dieting, as opposed to slowing it down.

JNE wrote:

FWIW, the little research I have done into IF suggests that there is no increased testosterone response until the HGH shows up several days into the fast (HGH and testosterone are highly correlated), and the HGH spike is likely one of the ways the body preserves itself by dis-promoting your body consuming muscle tissue for calories.  So yes, IF will increase your testosterone and HGH, but your gut and body will be so short of nutrient (this is what caused the spike in HGH and testosterone, so there is no workaround i.e. no way to have the hormone spike without the nutrient dificiency) that the spike won't make a meaningful difference because there is no material to build your body with.  Instead, your body will simultaneously reduce it's metabolism in order to maintain structure on the restricted calorie diet. 

 A better bet would be to find a diet which more closely matches your metabolic rate (as in carbs vs. protien vs. fat), eat frequent but small meals to get your calories, and don't overdo it.  Most people struggling with diet/weight/metabolism overdo it on the carbs (which have the fastest rate of energy delivery) which requires that their body store the unused calories.  Then, since the energy came on too quickly from the carbs, their metabolism has to slow down to be able to get by on the available energy it did get from the carbs which it did not store.  this causes a negative feedback loop of more fat storage and a slower metabolism combined with a constant feeling of hunger.  I contend this is the reason low carb diets are so successful for so many people.  The best workaround to this is to feed the body calories that it does not have to store (so more fats and protiens), that way you can maintain or even increase your metabolism via dieting, as opposed to slowing it down.

I agree with you on carb intake.  I was able to get my weight down to it's lowest in 13 years following low carb and i felt STRONG.  (well about as low carb as a vegetarian could get i suppose) could you counteract the nutrient deffieciency by just taking a multivitamin with your first meal? i've read some people take a shake of BCAA's while they're in their fast to counteract muscle break down. some would argue that this takes you out of fasting but as athletes i'd say it's a smart move. thoughts?

Lisa Haze wrote:

I agree with you on carb intake.  I was able to get my weight down to it's lowest in 13 years following low carb and i felt STRONG.  (well about as low carb as a vegetarian could get i suppose) could you counteract the nutrient deffieciency by just taking a multivitamin with your first meal? i've read some people take a shake of BCAA's while they're in their fast to counteract muscle break down. some would argue that this takes you out of fasting but as athletes i'd say it's a smart move. thoughts?

The nutrient deficiency I was talking about was a macronutrient deficiency (carbs, protien, fat), so no, taking a mutivitamin would not help in the slightest.  The big takeaway I get is that fasting will lead to a lower metabolism, which is the opposite of what a dieter wants.  Keep in mind this perspective comes from the assumption that people who store fat easily do so because they have a slower than average metabolism, and that the fix comes from getting the metabolism to increase while not increasing (and in some cases decreasing) overall calories.

Check out the book the Obesity Code, it examines several hundred studies and comes to the conclusion that we’re fat because American diets increase our insulin resistance, mostly through ridiculous amounts of sugar and bleached flour. I’ve been doing IF for 6 months, I’m 5’10” and went from 176 to 162. I do mostly 16 or 24 hour fasts (skipping breakfast and/or skipping lunch) Once you get past the mental part you quickly realize that you won’t starve and as long as you stay hydrated you won’t feel badly. I find that if I eat lunch I get tired afterwards, if I fast I am full of energy and don’t feel that post lunch desire to take a nap at my desk. 

As far as climbing, I’ve climbed while fasting for 24 hours and noticed no difference in the grades I can climb or my energy levels. I’m climbing at a higher level than 6 months ago, however I don’t think IF has hurt or hindered my progression, I think it’s stayed at about the same level before IF and during IF. That being said, being 14 lbs lighter is obviously a perk for climbing.

Those of you that do 24hr fasts, what does that look like?  I assume that you essentially eat one meal per day, and nothing but water for the remainder. How many calories do you take in?  Do you ever break the fast, or is it an everyday pattern? When do you consume your single meal? 

Quite frankly I think the fasting thing is some bs. I'm forced by an illness to do the intermittent fasting and low calorie intake thing a lot. It sucks. I get tired all the time and it gets hard to think straight. I was told by my nutritionist that it is important to exercise a lot so that the metabolism doesn't reset. So I am getting some nice muscles but I feel like shit. 

Also regarding the whole Paleo/our ancestors did it so it must be good thing - hygiene etc being what it was, a significant number of folks died long before they would have been old enough to exhibit signs of chronic disease. I recommend read Zuk's text Paleofantasy. Here's a link to a review https://www.theguardian.com/books/2013/apr/24/paleofantasy-evolution-sex-diet-review

I've been interested in IF for years.  I currently pay for Martin Berkhan's Patreon forum related to IF questions. It's interesting to realize why it does work and what there is valid proof for in active populations, and what there is not.  Unlike lots of IF proponents Berkhan was interested in it to look better and to make dieting easier. He doesn't make some faux science claims based on selective interpretations of studies (Rhonda Patrick) or extrapolate watered down anthropological evidence (Pilon, Hofmekler) or pretend that things we did thousands of years ago were somehow what we should now do in the modern world.  I find this a refreshing take on the normal dieting bullshit that circles around with each passing fad.

It's not magic.  Most of the studies are on sedentary or overweight populations.  The idea of carb cycling like IF or eating keto most of the week with a massive day is all minor hormonal changes in the scheme of things.  The body can go into ketosis in 1 day if a person exhausts their glycogen stores completely, but that is rare with climbing and even weight training. Then introducing tons of carbs in the next day essentially creates a minor zero sum situation that has not shown to be significant for long term hormonal markers or weight loss. In the few studies that compared IF to regular feeding in normal populations IF won out because of a very important point- people ate a tad less.

IF is a means to control calories. If you eat less over the week, you lose weight. You could do the same eating frequently and not having a big feeding window. You don't need to workout fasted or do anything that controlled.  In people with higher cortisol levels and some body types, it can be a disadvantage because it can blunt metabolic rate and increase cortisol output during the fasted state, which is not that ideal. 

In my experience the LeanGains style IF did not work. It was annoying to go from almost no starchy carbs on rest days to 300-400g on a climbing day. Keto leaves me feeling fairly flat and weak. And anything convoluted will just be annoying with work and life.  On the low carb days I was fine, but the high carb days left me feeling bloated and I didn't like encouraging gorging.  It also sucks to have a fuck ton of calories left and just slam down less healthy foods or have to pig out.  To me those are eating disorder habits.  That is shit anorexic people do.  It's fun socially, but not as a daily thing.  I also found I had a really, really hard time sleeping on this paradigm and I never figured out why.  I might try it again in the future with more fat.

I've settled on a middle ground, which is to be relatively consistent with macros and calories every day (45/25/35 or 40/30/30 split) with some extra food during training sessions. The fasting window is whatever works with my morning meeting and climbing schedule. I could climb and boulder fasted to a degree, but in longer sessions of 2-3hrs would rapidly shit the bed at the 2hr mark even with BCAA. Whatever underlying marginal gains that could happen were simply not worth the decrease in performance. So, what I try to do is if I have a morning climbing session I try to eat an early dinner to go as long as I can before climbing and have some BCAA right before, then eat my snacks as normal.  On normal days where I climb at night I tend to eat breakfast somewhere around the 10-10:30 mark after I plow through early morning busy work.  If I eat dinner at 7-8 the night before then that ends up being 14-15hrs, which is close to the 16:8. The extra hour really doesn't make a huge difference.

Matt Stroebel wrote:

Check out the book the Obesity Code, it examines several hundred studies and comes to the conclusion that we’re fat because American diets increase our insulin resistance, mostly through ridiculous amounts of sugar and bleached flour.

This is what I meant by the negative feedback loop.  Insulin resistance is just a measure of metabolism in that people with a slower metabolism have a higher insulin resistance.  I will illuminate this point with an example using made up numbers:

Take some random person with "high insulin resistance".  They need 150 calories to get through their afternoon (3 hours X 50 calories/hour), so they eat 150 calories of carbs, in this case sugar because it will help drive the point home as we all know sugar calories become immediately available i.e. the rate at which their caloric contents become available to the body as fuel is the highest of all possible foods.  So this person eats their 150 calories of pure, white, granulated sugar, and in the first hour their body gets all 150 calories dumped into it.  Since they only require 50 calories to get through that hour, and since past data regarding daily and hourly caloric intake suggests that increasing their metabolism to 150 calories/hour will be disasterous, and since they will not be eating for another two hours since they think they know they already ate enough food to get them through the 3 hour time period, their bodies only choice is to slow their metabolism to 50/3 calories per hour.  As a result their insulin resistance has increased.

If this person instead ate 150 calories of protien/fat, they would have at least maintained their metabolism, and then their calculations for how much  they needed to eat would be greatly simplified to the point of manageability.

climbing friend,

the fasting of intermittent style for your sexy muscles, myeah, it only is workign if upon completion of full fast you immediately gnaw the head off nearby crag dog and then scream top off your lungs with all your primal glory (activating enhanced ancient fat burning muscle building enzyme that it is proven to come during times of enhanced aggression), as did the cave peoples. the more adorable the canine its flesh you are eating, the finer the body composition you would be obtaining hyeahhh!!!!

I now leave you to resume your mediocrity for my most heroic session of campus board, 50 x 1-5-9 with weight vest utilized, which I perform twice daily to warm up for teh boulderz. 

do not feel bad I flash your project

JNE wrote:

The nutrient deficiency I was talking about was a macronutrient deficiency (carbs, protien, fat), so no, taking a mutivitamin would not help in the slightest.  The big takeaway I get is that fasting will lead to a lower metabolism, which is the opposite of what a dieter wants.  Keep in mind this perspective comes from the assumption that people who store fat easily do so because they have a slower than average metabolism, and that the fix comes from getting the metabolism to increase while not increasing (and in some cases decreasing) overall calories.

When you eat a large meal your metabolism revs up and you burn more calories than when you eat small frequent meals. I saw this doc called the science of fasting and it seems to disprove your theory. 

I have been doing it since about October now and I have got to say it works for me. I feel great most of the day ( I do note that I have significantly cut down BS carbs like bread and sugar as much as I can too which will have an effect on "feeling good". mostly carbs from vegetables and some occasional fruit). After about two weeks were I was pretty damn hungry in the morning, I am now totally use to it and I can easily go until 3-4 in the afternoon and feel fine having not eaten yet. Other than paying attention to crappy carbs I don't really follow any specific diet. There is really good information by rhonda patrick and satchin panda. She has a podcast with him which is really informative (her podcast is called found my fitness). She has also been on joe rogans podcast a few times and they are all awesome. She is very smart and can explain things really well. Worth looking into. If you are just starting though give it time your body will get use to it.

Lisa Haze wrote:

When you eat a large meal your metabolism revs up and you burn more calories than when you eat small frequent meals. I saw this doc called the science of fasting and it seems to disprove your theory. 

Since research shows metabolism is about an average, it can be possible that a bigger meal (temporarily) revs up your metabolism and that small and infrequent meals will increase your metabolism.  I will illuminate this point with another example:

Take three people, Bob, Aiden, and Sarah, all "insulin resistant".  Bob eats small and infrequent meals, Aidan large and infrequent meals (but tends to under-estimate their needed calories from time to time), and Sarah also eats large and infrequent meals (but tends to over-estimate their needed calories from time to time).  

Since Bob eats small and infrequent meals, he always eats just the right amount, and thanks to his disciplined 1 rep max focused strength training routine, develops a need for a greater number of calories over time*, thus increasing his metabolism.  

Aiden gets a nice metabolic spike after every meal, but suffers from a reduction in metabolism every time calories are underestimated.  As a result, over time Aidens metabolism is slightly slower than Bob's, and this is exacerbated by the fact that Aiden thinks lifting weights is dumb and so doesn't lift weights.  Additionally, Aiden sees only sporadic and plateauing climbing performance gains despite plenty of effort.  

Sarah, like Aiden, gets a nice metabolic spike after every meal.  However, unlike Aiden, she tends to over eat from time to time.  When Sarah does this, regardless of what food she ate (excepting the times when she gets just the right caloric ratios s.t. the rate at which the food is digested matches her metabolism.  However, since Sarah believes calories in = calories out is the only dieting formula she needs, the number of times she has gotten just the right ratio of calories could be counted on one hand.) she gets a strong insulin response meaning she stores the extra calories as fat.  Now, as in the case of eating too high a ratio of carbs, Sarah only gets to use part of her meal as energy and as a result has too few calories to get to her next meal at her current metabolism, so her body takes the path of least resistance and reduces her metabolism slightly.  As a result, over time, Sarah has a slightly slower metabolism compared to Bob, and this is exacerbated by the fact that Sarah has gained weight in the form of fat.  Thus Sarah suffers from chronic/terminal personal grade deflation, and largely gives up on climbing to become a supertopo troll/regular.

FWIW, my brief stint of research into IF can largely be summarized with this study which I read to say that fasting lowers testosterone and this other study which I read (in conjunction with the results from the previously cited study) to say that fasting will increase HGH (and therefore also testosterone) but only after 5 days, and then only for the preservation of non-fatty tissue which could otherwise be consumed for calories.

*Be like Bob.

JNE wrote:

This is what I meant by the negative feedback loop.  Insulin resistance is just a measure of metabolism in that people with a slower metabolism have a higher insulin resistance.  I will illuminate this point with an example using made up numbers:

You should have stopped there.  The metabolic increase do to the thermic effect of food is consistent for 1 meal or 5 meals.  However insulin resistance is not caused by a slow metabolism: a slow metabolism is more of a sign of insulin resistance.  Also, there is only one "fat storing" hormone - Insulin.  Limiting an insulin response has been proven to reduce the ability to store fat.  

JNE wrote:

Since research shows metabolism is about an average, it can be possible that a bigger meal (temporarily) revs up your metabolism and that small and infrequent meals will increase your metabolism.  I will illuminate this point with another example:

Take three people, Bob, Aiden, and Sarah, all "insulin resistant".  Bob eats small and infrequent meals, Aidan large and infrequent meals (but tends to under-estimate their needed calories from time to time), and Sarah also eats large and infrequent meals (but tends to over-estimate their needed calories from time to time).  

Since Bob eats small and infrequent meals, he always eats just the right amount, and thanks to his disciplined 1 rep max focused strength training routine, develops a need for a greater number of calories over time*, thus increasing his metabolism.  

Aiden gets a nice metabolic spike after every meal, but suffers from a reduction in metabolism every time calories are underestimated.  As a result, over time Aidens metabolism is slightly slower than Bob's, and this is exacerbated by the fact that Aiden thinks lifting weights is dumb and so doesn't lift weights.  Additionally, Aiden sees only sporadic and plateauing climbing performance gains despite plenty of effort.  

Sarah, like Aiden, gets a nice metabolic spike after every meal.  However, unlike Aiden, she tends to over eat from time to time.  When Sarah does this, regardless of what food she ate (excepting the times when she gets just the right caloric ratios s.t. the rate at which the food is digested matches her metabolism.  However, since Sarah believes calories in = calories out is the only dieting formula she needs, the number of times she has gotten just the right ratio of calories could be counted on one hand.) she gets a strong insulin response meaning she stores the extra calories as fat.  Now, as in the case of eating too high a ratio of carbs, Sarah only gets to use part of her meal as energy and as a result has too few calories to get to her next meal at her current metabolism, so her body takes the path of least resistance and reduces her metabolism slightly.  As a result, over time, Sarah has a slightly slower metabolism compared to Bob, and this is exacerbated by the fact that Sarah has gained weight in the form of fat.  Thus Sarah suffers from chronic/terminal personal grade deflation, and largely gives up on climbing to become a supertopo troll/regular.

FWIW, my brief stint of research into IF can largely be summarized with this study which I read to say that fasting lowers testosterone and this other study which I read (in conjunction with the results from the previously cited study) to say that fasting will increase HGH (and therefore also testosterone) but only after 5 days, and then only for the preservation of non-fatty tissue which could otherwise be consumed for calories.

 

*Be like Bob.

Ok I didn't read this. Because it went off topic. There are other factors in this scenario that doesn't prove your point.

Eric Carlos wrote:

You should have stopped there.  The metabolic increase do to the thermic effect of food is consistent for 1 meal or 5 meals.  However insulin resistance is not caused by a slow metabolism: a slow metabolism is more of a sign of insulin resistance.  Also, there is only one "fat storing" hormone - Insulin.  Limiting an insulin response has been proven to reduce the ability to store fat.  

You mis-read.  The claim I made is essentially that "insulin resistance" is an indicator of metabolism, meaning that if someone is "insulin resistant" you can pretty reliably (100% of the time?) conclude they have a slow metabolism.  To put it another way, I would expect "insulin resistance" is highly correlated to metabolic rate, with metabolic rate defined as the number of calories one needs to consume in order to maintain body mass.