Fasting boosts stem cells’ regenerative capacity (2018)
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Apart from physiological benefits though, the mental aspect of fasting from my own experience can be quite exciting as well. A 7 day fast was the longest I did so far, but 72h really hit the sweet spot for me. It was like a journey through my mind, I got challenged in very new ways to break the fast and also questioned my purpose in life a lot, as I seemingly live to eat. It was quite shocking to realize how much time I spend during a normal day to: buy food, prepare it, consume, dispose, cleanup etc. The rewards of fasting to me were long phases of absolute clarity and great concentration.
While she couldn’t do the several day fast, we found out that it was quite feasible to do the “one meal per day” thing, which shares a lot of the health benefits, and its a lot more forgiving.
I was under the impression that this was really unhealthy though. My BMI is 19 so I'm close to being underweight. Isn't this unhealthy? Do people fast and not lose weight?
The underlying psychological issues and associated stresses is what IMO qualifies as “unhealthy”, in which case corresponding under- or over-eating could result in malnourishment or excess weight[0]. However, in absence of these issues or other factors suppressing your body’s hunger/satiety messaging, not eating some “standard amount” shouldn’t be an issue on its own[1].
I happen to know a person who fasts routinely. In case of that person it doesn’t seem to be motivated by hidden psychological issues (he does not strike me as a person who could be suffering from body dysmorphia/anorexia) but by a conscious health choice. As an example of his logic, recently he got COVID and from his words he “simply” didn’t eat for two days and was right back on his feet feeling great. It’s not my place to question his choices, and I myself try to space meals to spend 14–16 hours without food every day since it seems to leave me feeling better, so it was surprising to hear but not too outlandish. He is not bulky but not skinnier than me either[2].
(I’m not a doctor, but from a cursory check medicine does seem to classify eating disorders as “expressive”, i.e. indicative of underlying issues. I don’t know how medicine treats under-eating without a cause, I certainly hope they don’t try to force-“treat” someone to make them eat at a level medicine considers “normal”.)
[0] For the record, I don’t think one can truly address those root causes just by eating less or more.
[1] In fact IIRC lower metabolic rates have been correlated with longer lifespans, at least in mice and in snails if not in humans.
[2] I’m slightly underweight, and can eat quite a bit without gaining much weight. My sister is similar, and she quickly gets low blood sugar shakes if she doesn’t eat enough. I guess it’s a sign of fast metabolism.
Interesting! Here's a challenge for you: could you buy — and eat — 5000 calories of chips/candy/soda per day for the next 90 days. You may not walk/run more than 5km/day, nor engage in other exercise for more than 30m/day.
Please weigh yourself before & after this experiment.
It's probably also better to ease into it. So start with an 8 hour eating window and slowly decrease the window.
Getting enough calories and nutrients can be a challenge and is far from easy with the "standard western diet". I would really recommend seeking advice from a professional.
Have you been to a grocery store in the last 100 years? Getting enough calories and nutrients is dead simple, our stores are overflowing with fresh fruit, vegetables, nuts and meat. What is the "standard western diet"?
https://en.wikipedia.org/wiki/Western_pattern_diet, also referred to throughout the article as "The Standard American Diet".
I meant the combination can be a challenge if your on a narrow time feeding window.
Yes, you say "maybe she had other compounding factors" which is equivalent to saying her case was idiosyncratic. In which case, why try to generalise it at all then?
When I look around the city, I see a lot of underweight women of all ages, including childbearing age — whatever the hell we're defining that as.* Many of them will be underweight by skipping meals, full on fasting, or eating and forcing themselves to throw it up later. This is the society, the mentality we have created.
Some of them I am friends with, others I have never met but write about it. Some claim to struggle with fasting, others fast and mention nothing about the difficulty or ease, and others struggle to eat enough. And some eat whatever they want and don't regulate it at all.
The takeaway is that when it comes to nutrition, there are a lot of factors and every case is idiosyncratic. There are no general rules other than "eat so you don't die", "don't eat so much you explode" and "don't eat toxic or corrosive chemicals". And even then, different people will have different tolerances to not eating, eating too much, and eating poison.
Nutrition is poorly understood, poorly communicated, and the driving factor behind the freight train of bullshit marketing telling people that they need to be wafer-like, elven creatures.
Full transparency, I'm underweight according to what I'm sure is actually a pretty shoddy measurement of weight...ness, but I don't do anything special. I fast quite a lot but I don't actually have a fasting regime, it's not planned, I just don't eat for extended periods of time.
When I do eat, it's really not a remarkable experience so I don't feel a need to change my behaviour. I eat enough to not die or suffer health problems thus far.
_____
* Since it will be a subset of {all ages}, my reasoning is covered.
He said they later learned it's known that women react to fasting differently and can have negative side effects, which we also discovered from our doctor when trying to get pregnant - so don't really see anything anecdotal there.
My point is that any nutritional thing is anecdotal because people don't neatly slot into a category when it comes to nutrition.
Also echo the mental clarity side of fasting. The weight loss was great, but how I felt was even better.
The crazy thing is, if you can get to 7 days, anything past that is just mental and you can go as long as you have the body fat to sustain the fast, provided you're keeping an eye on your electrolytes and not drinking too much water.
Don't you think it's too dangerous to name it essential life experience and recommend it to random people on the internet?
I'm really asking, I'm not knowledgeable about this at all, and my questions stem from pure gut feeling.
Obviously if you feel differently, talk with your doctor. I am not a doctor, and this is not medical advice. I thought that went without saying on the internet, but just to be extra careful, there it is.
Couple of caveats in the almost. Pregnancy, Eating Disorders, Elite Athletes functioning at under 5% bodyfat, and again the key word being _healthy_ here. If you have any kind of condition, disorder, disease, etc. obviously talk to a medical professional.
Most people just don't have the desire to do it, and if you're not used to fasting and eating a standard diet, the first few days will make you feel terrible both physically and mentally. Just like anything, it gets easier with practice.
That's sort of the rub in cavalierly recommending things to the general population, even when they're only somewhat extreme. There are plenty of undiagnosed conditions out there, and the further you move from the center of the distribution, the more you're going to sweep up potential risk in ways that aren't easily caught with a simple "not applicable if".
I say this as someone who fasts pretty often, though usually not more than 2 days. It's the same reason I wouldn't recommend everyone go out and take 200 mcg of LSD, "unless you have a mental health condition". This world of perfect information about one's own health that you're imagining simply doesn't exist. (Again, I say this as someone who thinks LSD is wonderful and salutary and has recommended it to many many friends in person with the appropriate personalized caveats).
Perhaps someone here with medical experience can chime in, but I agree 7 days seems a bit extreme for most people.
The only major health risk is refeeding syndrome, and even then it's only really notable if you're an alcoholic or have anorexia. If you're otherwise healthy with normal sodium/potassium/etc. intake and you take it slow when refeeding, I don't think it's particularly dangerous. Obviously, talk to your doctor, and it's probably good to get blood work before doing something like this.
There's just not a metabolic pathway for breaking down muscle/organ tissue for energy when you have adequate fat stores. We would have died off as a species a long time ago if that were the case.
In the grand scheme of things, if you have the body fat, 7 days is nothing for a fast.
Edit: To those asking, yes. I fasted for 60 days, water and electrolytes, no calories.
I remember his post from a few months back - found it rather inspiring.
Quite frequently I hit over 10k steps/day on my step tracker, sometimes double that. I live in the middle of a major city and walk everywhere, and this was before work from home.
If you’re looking for exercise/fasting advice check out my fat per unit time post elsewhere in this thread.
Humans have weathered long durations of food insecurity for much of their existence. If the default metabolic solution to fasting was harvesting energy from skeletal muscle and smooth muscle... well that strategy wouldn't work for very long, would it? The lowest hanging fruit is muscle/liver glycogen, and fat mass after that.
Breaking down proteins (gluconeogenesis) is a metabolically expensive process, requiring large energy input for low energy output. The body is wholly invested in protecting these vital organs. Skeletal muscle has a reputation for being fickle, subject to change based on stimulus and energy demands, but those adjustments are most significant and relevant to those who are invested in maximizing lean mass (athletes, bodybuilders, statistical outliers).
Fasting is relatively protein-sparing, all things considered. The observations of apparent muscle loss can be attributed to loss of muscle turgidity - a reduction in glycogen, intracellular fluid, and electrolytes. The difference between fed and fasted states, both visual and internal perceptions, are quite extreme.
Are extended fasts ideal, or even generally recommended, for someone with the singular goal of building muscle? Absolutely not. But it is a flexible tool when goals shift towards catabolic outcomes (losing weight). Furthermore, the downstream benefits of fasting can translate to improvements in insulin sensitivity, nutrient partitioning, muscle-building, and body composition... which are relevant to anabolic outcomes.
"A 27-year-old male patient fasted under supervision for 382 days and has subsequently maintained his normal weight."
By comparison 7 days is trivial. More to the point, a 7 day fast with medical supervision should be safe, if it is not, the supervisor will advise against it.
A better way of looking at it is to take it incrementally
* skipping breakfast
* skipping breakfast and lunch
* skipping a whole day
* eating one meal every two days
* eating one meal every three days
* ...you get the point...
I don't think OP would advocate just jumping right into it. Start small, work up from there, listen to your body. You wouldn't jump right into running a full marathon.
I believe I say multiple times in this thread nobody should just jump in and do 60 days, however I believe anyone (caveat-ed up thread) can 'jump in' and do 7 days at any point in their life.
It won't be easy, it'll be especially hard if you've never fasted before and are on a standard diet, but it won't be dangerous. It'll just probably be the most difficult physical and mental thing you've ever done.
Also, thanks for linking to my spreadsheet up there.
I'm not sure starting a western diet without medical supervision is a better idea given 75% of the west is overweight or obese. Unless you have medical conditions a 7 days fast is a walk in the park in term of health
Mistake 1: Drinking pure water. Your body does need some specific minerals even when fasting. Cole Robinson, a fasting focused youtuber (who is not for everyone), has shared a Magnesium, Sodium, Potassium, Sodium Bicarbonate & Water recipe he calls Snake Juice that keeps electrolytes steady during a fast.
Mistake 2: Drinking liquids that break the fast. I've watched youtube videos of fasters add things like diet soda, gatorade, and even jello to their fast. That defeats the whole purpose and negates any positive effect.
It's not that easy. You have to properly substitute electrolytes - sodium, potassium and magnesium. And that is almost impossible without small doses of carbs.
My longest fasting was 42 days. I did 28 days three times before. I'm fasting more or less regularly (once per year) for about 25 years.
Don't do very long fasting without guidance of a doctor. Your heart needs properly balanced electrolytes.
EDIT: I've just seen your other comments here also underlining the need of electrolytes. I still leave my comment here for the other readers ...
From what I've seen there is actually research into it and the weight loss/fitness benefits don't seem to be any better than any other calorie restriction when equating calories (slightly worse for muscle mass when combined with exercise in one study IIRC), and other claims seem overblown.
Layne Norton has a couple of good study reviews (eg. https://www.youtube.com/watch?v=0PyBoKSv2tI)
That being said - this is highly individual stuff - even if something doesn't work for 99% of people - it doesn't matter if it works for you - and it's easy to try.
It's just important to have realistic expectations about these things, because overhyping tends to lead to motivation spikes - you get enthusiastic and then you get disappointed and crash to 0.
I recently did a significant amount of caloric restriction, from probably 2500/day down to more like 1500/day. The first day was awful. The second day wasn't so bad. By the fourth day this new amount of calories feels fine. I had to give myself permission to do basically nothing for several days though because I just didn't have it in me.
Whatever you need to do or narrative to tell yourself why you don't need to eat, do it. Keep busy, work, clean the house or volunteer. By keeping occupied, the mind will not seek food out of boredom and ritual.
Eat once a day. Typically I "reward" myself with the evening meal after fasting through the day. There are different kinds of fasts but the one which seems to work best for me is 1-big-meal a day type fast. The rest of the day, I can drink water or black coffee.
1) Remove from your mind the idea that huner is suffering. It's all in your head. It's merely a mild discomfort.
If you ate last night and woke up in the morning, you are not hungry. You are just used to eat in the morning. Your body will not suffer any thing from skipping breakfast. It alerady has more than enough energy storage. It was designed to tap into it.
2) Surround yourself in a virtual environment where fasting and accepting hunger is the norm and expcted and obvious thing to do.
Read blogs about fasting. Watch youtube videos about fasting. Read books about fasting. Watch how people who consistently fast are healthy and fit.
3) Understand that there are two types of pleasure. Fleeting pleasures, and lasting pleasures. The fleeting pleasure are the sensual. They are momentary and quickly go away. If you spend your life chasing fleeting pleasures, you will be miserable.
Lasting pleasures - if you can call them so - are mental states. Contentment. Feeling in control of your life. These don't come from things. They come from what you value and the way you conduct yourself in the world. If you have no value, you will be controlled by your desires.
Some people think this is freedom: to do whatever you desire. To me, it's slavery. Because when you follow this path your life will be miserable.
Some people try to cheat by pretending that their misery is actually happiness. You see it in the people who insist that fat is healthy and beautfil and hot!
4) Understand that your mind is distributed. Even if you resolve to fasting, there will be some component of your mind that really really wants to just keep eating. Sometimes it might come out and win. Accept that such a thing could happen. When it does happen, don't be too hard on yoruself. Try to understand why it's happening. But anyway, go back right away. Understand that many other components of your mind want to continue doing the right thing.
And, of course, in mice.
(Still noteworthy if you are trying to understand why fasting seems to help with many different ailments.)
Best I remember feeling in my adult life was after a 60 day fast. Not what I'd do today, or at least not the same way, but I highly recommend every healthy human fast for at least 7 days once every couple years.
The plural of anecdote is not evidence, YMMV, consult your doctor, I don't even play one on the internet, etc.
That being said, I'm currently on day 3 of an extended fast myself.
That one was super strict, no coffee, no tea, nothing.
EDIT - Also, this is _not_ how I would go about this now 5+ years later with more experience under my belt.
Electrolyte supplementation on an extended fast is important, and I drank way _way_ too much water in the early weeks of that fast, which is also dangerous.
If you have some fat (75% of westerners are heavily overweight or obese) you can easily fast on water only for weeks, of course you're not going to be able to exercise heavily every day or run a marathon. But if you're an overweight office worker with no other health issues you'll be just fine.
For anything over a week you probably should get medical assistance to keep an eye on vitamins and electrolytes, but you're not going to drop dead/unconscious/destroy your DNA
What's dangerous is starvation, aka fasting until your body starts giving up, but for the average westerner that's going to take a long time.
I did not try to run quickly while fasting, but I did keep doing my 5km 3 times per week, and the gym. Anaerobic was hard and quickly tiring, but aerobic exercise wasn’t really any harder.
A friend did point out that my movement was “more economical” in general - I hardly lifted my feet while running or walking, and a few other things. But I didn’t feel more tired or more strained, except for unaerobics.
3) even if we assume in an ideal world, that the person who fast is able to supplement ALL the useful things and yet not take any external calories/glucose. This person would still reach a huge bioenergetic deficit/stress. Yes he will survive as you say, and might even be asymptomatic but nonetheless I would be very surprised if the biomarkers where doing Okay. Default bloodworks analysises are shit but if you command a proper analysis of your antioxidants ratio and of your bioenergetics biomarkers and apoptotic biomarkers you will see (unless I'm wrong which is very unlikely given my expertise) that the body is having a significantly accelerated aging/damage scheme. Which might not show symptoms before multiple decades later and even might not show symptoms at all in his life but statistically, there is a risk. Now he can mitigate some of those, by taking e.g. ALCAR + NAC daily for a year.
BTW the guy you linked died at 50 years old, which is not a performance.
All I'm saying is that you were wrong. The human body can take much more than you explained in your first comment. You won't die nor fall unconscious and "5-7 days max" isn't anywhere close to the limit
for bioenergetics I don't remember the relevant ones although the manifestation is not only molecular, it can be observed (mitochondria respiration rate, uncoupling, etc) maybe this paper can show the relevant ones? https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4715336/
Glutathione possibly needs to be included as this will get low and Choline or Carnitine to remove the brain fog that occurred.
Averaged 18kg weight loss over the 18days, never felt so good in my life, like being a teenage male ramped up on Testosterone again, amazingly easy to fall asleep, excellent quality of sleep, vivid dreams which are recalled in the morning, not nightmares or anything like that. Foods which I dont like because of historical reasons smelt appealing and I wanted to eat them, no cravings for anything.
The only water I could really wanted, was the Scottish Highlands water, just didnt like Evian, S. Pellegrino, and the supermarket brands, and I wonder if highly filtered water ie dead water with no contaminants so its almost pure H2O would have been what I wanted, but they dont sell that in supermarkets AFAIK.
Ramadan is one of the fasts where you dont consume fluids during the day, and not consuming fluids will ramp up parts of your immune system which is why its important to drink fluid in order to not get angry. This could be in part because histamine is used by immune cells to move through tissues, but a personality side effect of high amounts is increased aggression. Anyone who supplements with histidine a precursor for histamine may also notice increased aggression. ie explosive rage, so be careful.
During my fast, my sense of smell became super good but the smell of chlorine in the tap water was disgusting, I couldnt drink the stuff.
2-3 kg per week is a realistic number.
I just rolled into day four of a fast and the delta from two days ago is 3.72 kg.
Most of the weight you lose in the first 3 to 5 days of a fast isn't fat, its stuff in your gut and losing water as you draw down your glycogen stores.
Totally agree, but maintaining brain function is my priority the ALCAR may also help considering its similar to choline.
But I’m only looking for documented examples, not extrapolated theory (which is what your first response seems to be), as — already in this thread - we have examples of 60 and 380 day cases with no observable I’ll effects (and I’ll add my own, multiple 15-25 days over the years, starting about 25 years ago — with doctor verified no I’ll effects a month later in most of them)
I watched my dad do 30-60 days every few years growing up. He always said how clear it made him mentally and the benefits to his health also was visible (until today he mountain-bikes across South East Asia during winter and he is in his late 70ies).
Longest I did was 40 days. Started out with 10 days a few years earlier which broke my misconceptions about if I would be able to do it. Especially the 40 days has been a healing journey for me both physically and mentally. It also gave me massive confidence about my body and taught me more about my limits than what decades of running did. I wouldn't do this long again because I lack the reserves today. But 10-20 days every few years is no issue.
Estimating by weight loss my metabolism was still burning well over 2500kcal daily at the end of the fast.
An example:
A person with 14 % body fat and 74 kg body weight has around 10 kg fat. That is more than enough to go for about 30 days without any calorie intake.
I read a lot of research last years about the subject, try search for 'fat inflammation'.
Fasting and a more plant based diet seem to reduce chronic inflammation.
All human cultures with abundant food had fasting as a part of their rituals... except for the modern American one... which then spread everywhere through food industry funded "science".
It's not that fasting is healthy... it's the other way around... eating too much all the time is unhealthy. Fasting is the default.
The first time I tried a 7 day fast it was like you described, I made it to about day 5 and I couldn't take it anymore. I've done about six or seven 7+ days fasts and now it's not a big deal, I feel totally fine the whole time. If I haven't kept up on electrolytes, I might get a little light headed when I stand up, but that's about it.
I use an electrolyte mix that has sodium, potassium, magnesium, calcium, phosphorus and iron. It's a bit hard to find mixes that have phosphorus, and that's the main electrolyte that is depleted in refeeding syndrome.
Fasting is not just about not eating for 16 hours in a day. When you break fast, you need to watch how much you eat, and eat a lot less.
If you fast for 16 hours then gorge yourself, your stomach will keep growling and you won't be able to get used to being hungry and think about something else.
After a couple days of moderated eating + fasting your hormone levels will reach equilibrium and you won't feel hunger as intense / won't mind it at all.
I'm a muslim who fasts during Ramadan (no eating / drinking until sunset) for a month, and either because I'm just conditioned mentally or because my body adapts itself, I don't really mind being hungry after 2-3 days. And the less & lighter I eat, the easier it is.
Yes it absolutely does. You can do intermitted fasting for 10 years but most people will die when they continuously fast for more than 20 days unassisted by IV nutrients. Are we really on the same page here?
Your religious experience of skipping lunch and having a late dinner used to be my daily routine during uni, aside from a couple of coffees with a cig. Fasting for 12-16 hours is very different from fasting for 120-160 hours. Whatever you may think, you cannot be mentally conditioned not to eat at all. I'm having trouble believing that people extrapolate their experience of skipping a meal to not eating anything for days or weeks in a row.
It sounds like you went into it without understanding the processes that will be unfolding - you didn't do enough research, otherwise you'd understand the symptoms you described.
The first time you fast will always be the roughest - most challenging too, especially since you've likely been eating highly inflammatory foods your whole life, likely without any break - and so by removing those foods and that inflammation from your body and brain, your brain is going to start functioning differently - and better.
Your brain 1) has to prune the pathways that were dependant on such a high level of sugar in your system (and not running off of ketones), and 2) inflammation has a depressant effect on the nervous system - and so you're essentially self-medicating to depress yourself when eating inflammatory food - and when you remove that, that depression is going to life, so your brain is going to want to start working faster as well - and so there will be pathways that will want to open up again that are no longer being suppressed-depressed.
It's also possible you weren't drinking enough water - or something was off with the electrolytes amount; you don't need any electrolytes or supplements if doing 3 days or less.
Refeeding syndrome is also a myth or rather it's a concept that formed from misunderstanding and poor guidance: "you have to eat small amounts and reintroduce foods slowly so you don't cause X, Y, Z." Bullshit. If you're eating food that's harming you, that you're sensitive to and your body is sending you pain signals for - but then you ignore that discomfort and continue to eat it, eventually you'll get somewhat "conditioned" to it - so you won't feel it as much - but that pain/discomfort/disruption/signal will still be there.
When I break a fast - I've done many 3 days, a dozen or so 5 days, and a couple ~10 day fasts - I literally cook one or two massive high quality and high fat steaks and devour one immediately - and the second usually within 2 hours. I don't feel any discomfort after, and I can feel my body being happy, and my mood lifts as my body knows it has food again; sometimes I'll have kale and a pack or two of raspberries - but I usually only add that on the following day. Simple, non-processed foods that I know my body is fine with - and the steak and kale being highly nutrient and energy dense (for their food group).
I break my fast with, return to food I know my body is good with because I've done the work to figure out (and not only through an elimination diet but also diagnostics that's far more efficient and provides concrete results to follow) - rather than in an unaware-unexplored fashion ingesting whatever I've been relatively unconsciously been eating for most of my life.
It was only in my early 20s a doctor told me to stop eating wheat due to symptoms he saw I had. No one prior to that ever suggested food could have been a source of any of my problems. Soon after that I realized I was allergic to eggs, learning later it is specifically egg whites - to which my mother also later learned she is also allergic to.
The mind is a powerful thing and will allow us to do things that are harmful to us, even pulling us away from, disconnecting us from feeling, suppressing us from feeling this harm that we're doing to our body - whether from food or physical activity. Most people don't do the work to explore, in part because no one has explained it to them thoroughly enough for them to be motivated enough to try.
I'd urge to you to try fasting again - but also to be gentle with yourself, don't be forceful or violent with yourself. Just start doing 3 days at a time to start. Likewise, figure out what a healthy-clean diet is for you - nd do that diet for at least 3-5 days before starting your water fast so then you have good energy and nutrient reserves at the beginning of the fast. And then break your fast with that same diet. If you need help figuring out how to figure that out, let me know, and I'll do my best to help. I plan to eventually write a book on the topic, at least a chapter of it, but I don't have anything complete to share with you yet in this regard.
I'd also recommend you read this other comment I just made - which will help you better understand processes that occur during fasting: https://news.ycombinator.com/item?id=31409602
And here's a 30 minute video by Dr. Jason Fung explaining by water fasting is good, healthy, and safe for us (arguably unless you're underweight and don't have fat reserves to burn): https://www.youtube.com/watch?v=tIuj-oMN-Fk - Dr. Jason Fung - 'Therapeutic Fasting - Solving the Two-Compartment Problem'
Time-restricted eating and concurrent exercise training reduces fat mass and increases lean mass in overweight and obese adults
At least no more than I would just sitting on the couch doing nothing.
Maybe body builders lose lean body mass when they fast, but it does not seem to hold true for the average human.
You need an expensive Dual-energy X-ray absorptiometry scan in order to precisely tell the body mass composition.
My anecdotal experience: I lost weight via alternate day fasting and did indeed shell out the 120 euro that two scans cost me. I lost mainly fat, my lean body mass after 6 months was down 4 pct, within error range I'd assume. I worked out normally through the entire period and even did things like a 200km bike trip during a 72hr fast. (I did a few of those to compensate for not fasting on holidays). Great experience, never felt better tbh.
One thing I think I learned was the exact threshold of power that allowed me to keep burning fat. Its hard to describe the feeling but after doing this for months (over a year by now) I think I know exactly when I can still push and continue on fat, and when I need to slow down to prevent lbm loss. Doing sprints, short intervals etc. would likely cause me to break proteins in the body and indeed be counterproductive - but here more research is probably needed, and individuals will likely have different thresholds.
The new equation [%BFNew = 6.083 + (0.143 × SSnew) - (12.058 × sex) - (0.150 × age) - (0.233 × body mass index) + (0.256 × waist) + (0.162 × sex × age)] explained a significant proportion of variance in %BF5C (R2 = 0.775, SEE = 4.0%). Predictors included sum of skinfolds (SSnew, midaxillary, triceps, and thigh) and waist circumference. The new equation cross-validated well against %BF5C when compared with other existing equations, producing a large intraclass correlation coefficient (0.90), small mean bias and limits of agreement (0.4% ± 8.6%), and small measures of error (SEE = 2.5%).
Generalized Equations for Predicting Percent Body Fat from Anthropometric Measures Using a Criterion Five-Compartment Model Zackary S Cicone, Brett S Nickerson 1, Youn-Jeng Choi 2, Clifton J Holmes 3, Bjoern Hornikel 4, Michael V Fedewa 4, Michael R Esco 4 Affiliations expand PMID: 34310492 PMCID: PMC8785250 (available on 2022-12-01) DOI: 10.1249/MSS.0000000000002754
This is delusional.
And bodybuilders DON'T lose fat when they fast because they take supraphysiological doses of hormones (steroids) that prevent the body losing muscle - and usually eat protein throughout their fast too. So not a good example.
Aren't these contradictory? If you eat (protein or otherwise) you're not fasting.
One starts to loose lean mass during prolonged calorie deficit which takes months.
At low intensity exercise you can just burn just fat.
The body can only get so much energy from fat in a given time, so at higher intensity levels it will try to get energy from both fat and stored carbohydrates.
Once you run out of easily available carbs it will try to supplement energy from the next available store, which is protein. i.e. muscle.
So this will happen well before you run out of body fat.
You can apparently increase the amount of base energy you can get from fat by training cell mitochondria with lots of low internet exercise.
Eg lots and lots of zone 1 or 2 on the Coggan zone system.
People think about fat as if they have access to it all, but it's a surface area per unit time problem. Like all the chemistry in life, on some level, it's diffusion limited.
What you should be thinking about while fasting is not letting your basal rate/time + exercise expenditure/time exceed your total energy available/time. I got pretty good at estimating this, but I wish there were an easy way to measure it.
Everything is stream processing, not discrete units.
It can also explain why ketogenic diets work for many people - if you exercise every few days, your body will maintain sufficient blood ketone level for your exercise days, but unlike glucose, ketones that are not used get peed out eventually (and not stored/converted back to fat).
Couldn’t find anyone knowledgeable enough to confirm I am right, but also no one to tell me I’m obviously wrong - still looking for one of those answers.
Apologies for not including that, I guess I just assumed it was common knowledge? Mea culpa.
> https://www.hawaii.edu/news/2020/10/09/intermittent-fasting-...
Considering Body Builders don’t fast, I tend to believe the study.
Yes, if you fast without exercise, you will almost certainly lose muscle.
And if you fast without nutritional changes, you likely won't lose much, because IF on its own does not equal a deficit over more than hours at a time.
I gained muscle on IF with ease, and I also lost far more than in their study, with ease.
I'm surprised, given the constraints of the study, that there was an average loss at all.
There's entire bodybuilding schools (such as LeanGains) that build on intermittent fasting, and its increasingly more common when it comes to cutting fat. Where did you hear this?
> 116 overweight and obese participants
Yeah I mean IF isn't magic. If you sit in front of netflix and eat three 800cal bags of chips it doesn't matter much if you're doing IF or not.
I'm doing IF for years and go to the gym every other day, most of the time fasted. I made good progress, lost fat, gained muscles, and most importantly I feel amazing.
Eating schedule is only a part of the equation. You still need to eat proper food and exercise.
In general intermittent fast is not a good way to loose fat precisely for this point. In Russia there are fasting resorts where people do not eat for 2-3 weeks under medical supervision. Most people do it not to loose weight but try to improve various medical conditions. Those who go there for weight loss typically gain the weight back since they do not change their eating habits.
As for bodybuilders they do intermittent fasting but not to loose fat but to gain muscles. For some people this works as long as they eat sufficient calories.
Here one can read about the "safety" of ca 60 days hunger strikes. See the section: "People who died on hunger strike"
https://en.wikipedia.org/wiki/1981_Irish_hunger_strike
The oldest one died at age 29.
Bonus: "Other participants in the hunger strike". Column: Reason for ending the strike
One poor guy got a perforated ulcer and internal bleeding after 13 days.
These people are either overweight or even obese, or just lying to you, or lying to themselves (e.g., drinking juice and coffee, or getting calories elsewhere and not counting it). Also, I guarantee they're completely sedentary.
If you're reasonably physically active (especially if you do any weight training) and you're in a prolonged caloric deficit while already being lean, you will lose muscle mass and bone density, and ultimately get injured:
Firstly, as you keenly note, we need to define terms like fasting. The kind of fasting people are doing for extended periods always includes water, but more than that, for an extended fast, it also includes electrolytes, and sometimes other nutrients.
Secondly, 60 days is a very long fast. While people are going to point out cases of people fasting for a year or more, the fact is that those are in the extreme minority. Most people consider a 10 day extended fast to be a very long one. A sixty day fast is far different, and there are studies that show negative effects of very long fasts, rather than "medium length" fasts such as seven days.
Third, I think it's a bit of a mistake to conflate a week long fast (what the post is about) with a 60 day fast.
Fourthly, most of the people talking about having done extended fasts talk about doing it in the same way one might talk about running a race- with practice. You'll see people talking about one meal a day, then a 24 hour fast, 48 hour, 72 hour, and then a week.
That gives the body a chance to adapt to the fasted state. These are health conscious people doing a health conscious thing.
Lastly, though, an ulcer isn't caused by fasting. Most ulcers are caused by infection, which was only discovered later in the 1980s. The kidney obstruction could be made worse by dehydration certainly, but it's still not causal.
People do need to eat, and extended fasts can be very dangerous, but there's such a world of difference here that I think it's not worth discussing.
That definitely isn't what anyone is suggesting. The people fasting these days for 50+ days with no ill effects are significantly overweight sometimes on the order of 100+ lbs. They can lose 60 lbs over similar duration which would kill someone underweight but leave them still technically obese.
Someone fasting for health will stop once something starts to feel off unlike hunger strikers who experienced serious declines before death. Sudden death from malnutrition during a fast while feeling fine at a normal range bodyweight isn't really a thing.
The 155lbs for a chap in the 1980s was certainly in the middle range. Check his wiki page: for sure he didn't look anorectic in the picture taken at the age 19.
More importantly:
Seems that we are entering the True Irishman or Scotsman territory:
Fasting 60 days is super safe but apparently only if you started with 300lbs, your weight did not drop "significantly" more than 4lbs below 100, you have no preexisting conditions, take balanced drinks with electrolytes (btw at least some IRA prisoners took water with salt) and you may take some nutrients and call it fasting.
Yes?
The photos I have seen of Bobby Sands show him to be taller than his friends and sknny... unusually skinny by modern standards. This person cannot safely lose 60lbs of bodyweight, others can:
https://www.theguardian.com/film/2016/aug/04/bobby-sands-66-...
Check 5 demands 9f the hunger strike.
Nothing about food or medical treatment.
British prison certainly was no joke (solitary confinement as a punishment i.e) but not exactly a gulag.
The research going into this over the last few years is off the charts.
https://www.healthline.com/health/autophagy#:~:text=Autophag...
So, some mechanisms are designed to kick in when you're eating food, and some other mechanisms are designed to kick in when you're not eating food.
By not having any period of time when you're properly hungry, a lot of the body's builtin mechanism never get a proper chance to fully kick in.
Here's to hoping that the cost comes down and insurance starts to cover it.
I hope soon the doctors can find the source of the pain. Kaiser refused to do anything over the course of years. MRI in a couple weeks once new insurance gets around to approving it. Why do we put up with this in the US? :(
Physicians for national health plan. They're actually making moves.
Also, to echo the top commentator, aside from the physical benefits of losing weight; another great effect is the mental clarity that fasting gives since less attention is given to eating and so moving away from living to eat.
Also, sugar drinks is fine I think, and is an easy way to get some energy in moderation.
"We go out of our course to make ourselves uncomfortable; the cup of life is not bitter enough to our palate, and we distill superfluous poison to put into it, or conjure up hideous things to frighten ourselves at, which would never exist if we did not make them."
2. Some of those (cold showers, fasting) have proven benefits. Are you arguing the benefits aren't useful or that all the existing studies are flawed?
There's also 3 of why'd you comment on something if you don't care about it but as I'm doing the same I can't really argue that fully.
1. The heart is a giant muscle and needs balanced sodium and potassium to function. There are electrolyte blends in the market designed for fasting to help with this.
2. You're insufficiently hydrated because you've reduced your drinking intake or haven't replaced the water you would get in your food itself.
3. The body is in a state of hunger and alertness. Your sympathetic nervous system is ratcheted up in awareness of this and in search for possible food. To calm this down, practice diaphragmatic breathing exercises.
In all medical supervised fasting clinics they don't allow a pure water fasting. A small dose of carb is highly recommended for absorbing and buffering the electrolytes.
- One meal a day
- No meat, lacticinia, or alcohol allowed in the meal
- Water allowed throughout the day
But all other things are not equal, so: No.
Only taking the food away or adding low quality food will most likely not solve anything
1. Was the study a human study or mice study?
2. If the study was human, how long should one fast for?
3. If the study was done on mice, what would be the equivalent hours of fasting in humans to observe same benefits? For example, rats fasted for 3 days experience autophagy, but rats would die if fasted for 5 days, so that 3 day cannot be applied to humans without an equivalent inflation of the time frame.
3. Was fasting the trigger or the resultant calorie restriction?
Thanks
Need a human study to answer other questions.