I had a huge drop in blood pressure once I started fasting daily. Even though I lost only a modest amount of weight (approx. 10 pounds; I was never obese, only slightly overweight with BMI cca 27), my blood pressure plummetted from 150/95 with medication to some 115/75 without medication within a month.
This holds even when I no longer fast daily, only a few times a week. Additional Concor, taken against post-Covid arrhythmias, reduced my BP to some 105/70 when relaxed. Going any lower would actually mean a risk of fainting.
This seems to be consistent with the theory of gut microbiota being reshaped. I can also tolerate milk slightly better than before; my tolerance still has limits, but I won't get a rash after a single cappuccino, which I most definitely used to before.
Last year I fasted for a week just to see if I could do it, I really wish I had before/after stats and bloodwork done. I don't think it's something I will do again.
It depends on your internal (fat) reserves. I'm 58kg 1m83 (BMI 17.32), so I wouldn't really try such a long period. But there are days I eat a lot, I build some glycogen reserves (easily available fat, made from glucose) due to my diet with much fruits, or other stuff like rice, honey, then the next days I can fast intermittently and use that glycogen. As a result I can't really gain weight, it always balance itself to that weight.
I think people with more weight, have deeper fat, and it'll take longer to use it. I remember seeing an article that our ancestors possibly were hibernating. The more fat, the more time you can spend fasting, even on a dry fasting (fat holds water), but in that case it's important to limit physical exercise
Well I would say that it gets easier as you go, other than you feeling progressively weaker and weaker. You probably made it through the worst of the hunger and cravings at 70 hours
At the 70 hour mark, I wasn't exactly hungry, but a bit irritable, cold and distracted. And yes, a little weaker. Pulling off any demanding work in that condition would be nigh impossible for me.
Wow I start to pass out at around 2pm and I get a terrible migraine past that if I haven’t had breakfast. But I’m only 130lbs and 5’11” so I don’t have much storage and usually have hypotension. I wonder what would happen if I push it
Do you mind sharing your daily fasting routine. I only tried intermittently and always wanted to give it a more serious try and I have to start somewhere.
I prefer to go without breakfast and have a lunch and a dinner 6 hours apart, because I hate to sleep with an empty stomach. I drink unsweetened coffee and tea (0 calories and may act as appetite suppressant). I generally limit sugar in my food, though not to zero.
On my non-fasting days, I have a breakfast, but I try to have no more than 3 meals a day. No snacking.
I decide whether to fast or not by the state of my hunger in the morning. If I am ravenous, I have a breakfast and a non-fasting day. If I feel only slightly empty, I go without breakfast to a total length of 17-19 hours of fasting.
I am now experimenting with continuous glucose meter to find out what meals send my glucose too high. This, again, seems to be individual. Rice and potatoes seem to act really crazy. Interestingly, pizza not so much.
18/6 has never done anything to my BP, I've been doing it for 10 years.
I suspect the biggest impact was trying to lose weight and changing your diet. In my case changing my diet has noticeable and immediate effect to any physiological metric than any other "trick".
I didn't change composition of my diet much back then, but I noticed that on days when I fast longer, my BP goes even lower. I could probably fast myself into lightheadedness now on Concor (not that I want to).
People are fairly diverse, so different reactions are to be expected. Our gut microbiota is diverse, too.
I also noticed that even slight amounts of alcohol (1 glass of wine) are visible on my BP for about 24 hours after. An increase of 5-7 points.
Abbott FreeStyle Libre first generation, which is the only one available in my country. I know that there are newer generations of the sensor, but I do not want to go through the hassle and extra expense of importing them from the UK or so.
What was your fasting routine? and for how long did you do it? Just interested in seeing what others are doing. I know there's 16-8 (16 hours no-eating, 8 hours where you can eat).
I don't tend to experience hunger and, as a result, interrupting my activities to eat multiple times per day can feel like a bit of an inconvenience. So I've frequently fasted daily since before "intermittent fasting" entered the common lexicon. It's not really intentional though, I will quite literally forget to eat or otherwise just don't make it a priority.
In my experience, I'm not sure it's quite the panacea it's sometimes made out to be. Perhaps there are psychological benefits to intentionally fasting that I'm missing out on. In any case, quite often when I'm wondering why I feel like shit I end up realizing something like I haven't eaten in 24 hours or in the last 48 hours I've eaten less than 1000 calories. Oops. I'm trying to be better about regularly eating 2 meals per day because I really do feel better if I've been eating consistently.
I'm not sure it's doing my blood pressure any favors either. Despite regular fasting and having a BMI of 18.1 (technically slightly underweight, as the lower bound of a "healthy" BMI is 18.5), my blood pressure is usually around 140/95. But who knows, maybe it would be higher without the fasting.
Intermittent fasting is not the same thing as malnutrition or fasting in excess. Continually not eating for 24-48 hours and/or depriving yourself of necessary calories isn't good for anyone.
The gut biome must be at least strongly influenced by the environment you create - change should be assumed as soon as you change that environment.
But does the change mean anything?
I think this is going to turn out to be an incomprehensible problem that we will never really get a handle on due to the time it would take to even begin to understand things. We just aren’t able to run those experiments and this is the general domain where science for us fails and degenerates to just-so stories and observational correlations “studies.”
To illustrate…
Last year I did 5 months of OMAD to lose weight. I’d gained a bunch in the first few months of lockdown. It wasn’t hard but it wasn’t easy especially because my wife, who is effortlessly slender and eats a ton, needs to eat a big breakfast every day.
I often wonder if a gut biome transplant from her would give me that - I’d love to see someone actually do that experiment.
But not on me.
Her and her brother can literally eat bags of iced mothers cookies per week and stay slender - her GP says she needs to gain weight. It just isn’t going to happen. It took me awhile to understand what’s going on but my observation is they get really warm and fidgety for the hours after overeating and just burn it off sitting there. Her whole family is pretty lazy, they don’t exercise recreationally. They aren’t running it off or whatever.
Whereas my chronically overweight family lives ends up with moderately high boood pressure, they also all live long lives mostly free of debilitating illness until the end. Her family, on the other hand, has all manner of terrible issues once they hit their 70s…
Obviously this could just be “genetics” but whose? Their nuclear genetics or their inhabitants? And do the long terms come out of that?
I honestly don’t think we will ever know without experiments. And given things like the above I wonder if they can be even done, even if you decided to ignore the potential long term…
Maybe it's this? Peter Attia https://www.youtube.com/watch?v=U3oI104STzs especially from 8:45 when he talks of the people who stay thin (which is worse for them, if they actually are insulin resistant)
Unfortunately, no. It was a theory put forth by a researcher on a podcast.
It makes complete sense to me, but I don't know how you'd even design an experiment for this. Maybe continues glucose monitoring along with identical diets for people of various body fat percentages?
> I often wonder if a gut biome transplant from her would give me that
Our urine is charged with more or less of our gut biome, and enzymes, not only toxins. so maybe.. drinking it (some people do, at least it's not dangerous)
You could consider switching diet to reshape your gut biome. Some people advise no-sugar diet, but in my case, I switched to a monkey diet, a lot of fruits, and lost a bit of weight (I used to be more 65-70kg for 1m83, now at 58kg) and gained energy, vitality, immunity (never ill), overall health, I can eat only fruits during some days or weeks. When there are less fruits I'd eat rice, lentils, honey, more rarely fish. So maybe try to switch your diet, find the one that works the best for you
58kg for 1m83 are you feeling OK? When I left home a 18 I was same size 55kg and I was... Very very thin. Pictures from then are kind of frightening. Not for lack of trying, though. I'd eat 300-500g (half a pack or the whole pack) of pasta 10 times a week, kilograms of cheese and looots of beer&wine, without ever taking 1kg on the weekly weight check...
totally OK, I have thin members, for example I can join my thumb and index finger around my forearm. That's why the BMI scales are not really meaningful, because I'm not underweight. I'm 36 now, and know myself better, between 18 and 23 I was more around 65kg, then I changed diet to fruits (because I started unsold fruits and legumes, against food-waste), and never felt so energetic and good. 54kg starts to be underweight for me
Happy for you then! I wasn't thinking BMI but worrying about a fellow very-thin/tall, from personal experience.
I didn't feel 'bad' then when I was so thin, mostly I could eat anything in any quantity and feel fine. Things like 2 or 3 large pizzas and still room for desert... but when I look at pictures I didn't look very healthy. But yeah, each body/morphology is different :-).
I think I messed up something with my hormones or something during my first year in college where I death-marched myself to study constantly until 5am, 'sleep' one hour or (luxury!) two and cold-shower myself into the next day, for 7 months. I felt so behind in everything and I hadn't learned to 'work' or 'study' in school, and I so afraid to fail and be poor fir life that I drained every ounce of anything I had to get by...
Summerbreak of that first year in college, once exams and projects were done, I slept for 2 months, mostly waking up to eat, play console, read and go back to sleep... That september I was 130kg (from 55kg, still I have the stretch marks) it didn't hit me until November that my body had changed.
Strangest thing then: I had gained so much muscle! I still don't really understand why. End of puberty I guess, but all so fast!
Makes me wonder if having a higher metabolism somehow "wears out your body faster".
My wife and I are the opposite. I can eat a cheeseburger every night and stay slender + low chloresterol etc. I do OMAD twice a week, which probably helps a little. It doesn't feel natural to always say three meals a day.
I actually feel great doing OMAD as long as I eat by 3pm. That works great for me and I guess I should have mentioned that to tie up the fasting part of that post. I lose about 2lbs a week as long as I’m doing it, more if I stop lifting (which is exactly why I keep lifting while doing that).
It’s just challenging in the context of real life. A friend wants to grab lunch, a friend wants to have dinner, my spouse the Cookie Monster is busy polishing off three eclairs next to me while I’m having my morning black coffee.
I recall a paper (I can’t locate it) associating high levels of metabolic activity with disease.
For example if you have an incredibly physical job and put away 8000 calories daily but maintain a low BMI you suffer more cell damage. Similar for users of stimulant narcotics (legal or illegal).
Perhaps a reader here is familiar with this study.
I just did a 40 hour fast to see if i could do it and it was a lot easier than i thought it would be. I'm trying to build up to a week long. We'll see how it goes.
It's a shame that fasting has been eliminated from the culture, but i guess that's what happens to things you can't make money on.
Hey man, sorry to call you out. I want you to find where you heard that, and maybe post it here so that we can review.
I have fasted many times for that length, and I happen to already be thin. Never even got close to refeeding syndrome.
I've read a variety of books on the subject. I've spent some time on PubMed. I don't know everything about fasting -- absolutely not -- but I know enough to say that you might be misremembering the time it takes to get refeeding syndrome.
I personally believe the number is closer to 30 or 40 days. We are talking Christ-level fasters, hunger strikers, performance artists, or concentration camp victims.
I downvoted your comment because I consider it to be spreading misinformation, and because your tone indicates that you have expertise or experience on the matter.
You can definitely get refeeding syndrome after 7-10 days of fasting. It depends on your your fat reserves, health, and lifestyle.
Say I'm 192cm and 69kg. My BMI is 18.7, which is definitely low, but perfectly healthy. I have an active lifestyle and burn 3500kcal per day. If I fast for 7 days without changing lifestyle, I lose roughly 7*3500/7700=3.2kg of bodyweight. By that point my BMI is 17.9. According to this paper[0] with 632 citations, anyone with a BMI <18.5 who's not eaten for more than 5 days is at high risk of refeeding syndrome.
If you think the numbers are fictional: those are my numbers from ~5 years ago.
I wasn't making "my point". I just knew your comment about 30-40 days and the random mentioning of concentration camp victims was absurd, and it clearly is according to official clinical guidelines. So no, I won't "just check online".
> Historically, some of the earliest reports of the refeeding syndrome occurred in starved patients in wartime such as Japanese prisoners and victims of the Leningrad or Netherlands famines. In general, those individuals with marasmus or kwashiorkor are at risk for the refeeding syndrome, particularly if there is greater than 10%
weight loss over a couple of months. Patients are at risk if they have not been fed for 7 to 10 d, with evidence of stress and depletion. However, more specifically, this syndrome also has been described after prolonged fasting, massive weight loss in obese patients including after duodenal-switch operations, chronic alcoholism, prolonged intravenous fluid repletion, and anorexia nervosa. Anorexia nervosa is one of the more common modern clinical presentations of the refeeding syndrome, as are oncology
patients undergoing chemotherapy, the refeeding of malnourished elderly individuals, and certain postoperative patients.
I did a week long fast. My advice is to be constantly drinking water and sleep as much as you can. Make sure you get enough electrolytes in your water or you will start feeling like you're gonna have a heart attack.
So many gurus right now make a ton of money from the IF (intermittent fasting) craze. You CAN make money off fasting. Sell books and courses. Promise a lot etc.
You can only make money through courses etc. if the methods aren't already in the culture, and relative to the amount of money you can make selling junk food or health food/vitamins/supplements, the books and courses are a pittance.
> Surely you need something beyond water for such a long fast right?
You need electrolytes for sure; but unless you've recently been prepping for a body-building competition, you don't need any calories for quite a bit longer than that. I did a week-long fast for religious purposes many years ago, before the whole IF health craze was a thing. All I had was water, and occasionally some salt. I still had plenty of fat at the end of it, and I wasn't particularly heavy before.
According to the book I read at the time (again, focusing on fasting for religious purposes), it's only after 3-4 weeks that a typical person experiences a more urgent type of hunger pang, which is the indicator that your body is starting to cannibalize critical infrastructure (and that it's probably time to stop fasting if you don't want to damage your health). People who are actually overweight presumably have enough calories to last for months.
Vitamins and minerals are obviously another thing. You're not going to get a nutrient deficiency in a week, but you might well in a month or two. (I am neither a nutritionist nor a doctor.)
If you'd never run before, you'd feel like crap after running 2 miles. Nonetheless, your body is designed to run; if you have a typical human body, take it slow and keep training, it won't be long before 5 miles is totally do-able. (Obvs individuals will have specific limitations.)
It's the same with fasting: If your body isn't used to fasting, you feel like crap; nonetheless, your body was designed to fast. Take it slow and keep practicing, and the rust will work off all those unused chemical pathways handed down by your ancestors. (Again, if you have diabetes or hypoglycemia or something like that, maybe fasting isn't for you.)
Because your body isn't used to running off its own fat. If you're on a keto diet you can effortlessly skip meals, but the initial switch to a keto diet is hard for the same reason.
Average healthy but overweight (yes I know this might be a contradiction in terms) person can fast that long pretty easily without eating anything. That's why the body stored the fat in the first place...
Fasting was one of the most memorable and shaping experiences of my life. I fasted for three days (72 hours of nothing but water) and observed so many interesting and fascinating things happening to my body each day: skin flare ups and subsequent clearings, changes in mouth and gut odour, periods of brain fog and brain clarity, cravings followed by complete loss of feeling of hunger. Every passing day had different effects. The most memorable was an astronomical improvement in my olefactory senses. By day two I was able to pick out the smell of individual ingredients in any dish being prepared in my vicinity. By day three, I lost the majority of my muscle mass.
The one and only time I ever did this was when I was young and in extremely good health (daily intense exercise, excellent diet, no health conditions). Slightly worried about doing it again today. Also, quite concerned having since learned that brain mass is the first stored energy source your body will go after during what is effectively starvation. Perhaps someone more knowledge on here can comment on how true that is.
I highly doubt you lost the majority of your muscle mass, unless you had very little fat on your body. More likely is you depleted all glycogen stores in your muscles which is mostly water, making your muscles deflate significantly.
Maybe you're right. It was a long time ago. The only points of data that I have is that I had a "college athlete" level of fat around my heart as per my sonogram and it took me months of work to rebuild my muscle mass.
I have been intermittant fasting for a month now and the results are fantastic. The mental clarity alone is worth it, let alone the weight loss and general well being (better sleep, better digestion)
I only eat for 4 hours a day, some days 1 meal and grazing, other days 2 meals, but nothing outside those hours except water and tea (with no milk)
I feel fantastic, I'm never going back to any other food schedule.
The downside was that the first week was incredibly hard, I felt dizzy and had spells of intense anger, but I distanced myself from those I love so as not to accidentally explode at them and just got through it, now after nearly a month, it feels normal and I just feel great. Highly recommend it.
IF is great. I've been doing the 8 hour window (basically skip breakfast) for years. When I started I was also an eat as soon as I get up person. It took about a week to get past that feeling (headaches, agitation, etc...). Now, I don't ever really get hungry. I get up, work out, train BJJ, work, etc... all before lunch and have plenty of energy and clarity.
I leaned up which was fine, but I've had to add some grazing in to stay at my goal weight.
I know this is rude but what was your weight before you started? In my experience and what I've observed, people who chant praises of weight loss techniques always fail to disclose that they were overweight/obese (in the technical bmi sense). It isn't hard to lose weight when you're in that category at all. Everybody who is in the obese category can lose 20-30 lbs in about a couple of months without question simply by maintaining a decent sized caloric deficit. Intermittent fasting was not what caused you to lose weight. It is just a fad esoteric movement that instructs you to have some self restraint. Kinda like a religion.
The one tried and true, definite till the end of time means of losing weight is a simple caloric deficit. Eventually with intermittent fasting you will hit a wall because you still consume the same amount of calories and your body will adapt to the schedule. It will consume your energy over the course of time as opposed to immediately which will halt your weight loss.
I speak of this as someone who essentially did intermittent fasting unintentionally. I would skip breakfast and not consume anything besides coffee until 12:00. My last meal would be before 20:00. So essentially I'd go 16 hours without eating. I couldn't lose weight because after I got done exercising, I gorged. I replenished every calorie I burnt off on top of the residual I also could consume for the day. My stomach expanded to be able to hold the large amount of food intake too. Once I ate smaller portions over the course of the day, not only did my caloric intake shrink (because I helped shrink my stomach back down to size before feeling full), but I couldn't eat as much. So I felt "gorged" on 400-600 calories.
Don't listen to that "2000 calorie" rule. That is for people who exercise significantly or have physical labor jobs. When that number was created, it was assumed people worked physically. If you have a sedentary job, you do not need more than 1200 calories a day and can very easily get your nutrients with just that alone. If you exercise, it gives you an additional reason to eat more and more opportunities to replenish said nutrients.
It’s not rude I don’t mind, I started at about 115kg, and I’m about 105 now, in about a month.
I will also add a wee disclaimer: I’m also exercising a lot too, I walk 7km every second day, so no doubt that’s contributing.
I’m happy with the weight loss, but really the mental clarity that comes with IF has made me a much better programmer, I’m 36 now, and I feel like I have the energy and mental clarity like I was 18 again. Even if IF didn’t give me the weight loss, I would do it for the mental clarity alone.
Yeah I totally get that IF isn’t for everyone, I have been overweight my entire life, since very early childhood and I tried many different things, the smaller meals, cutting out carbs, vegan, no sugar, and they all worked to some degree, but the weight and bad habits always came back.
IF has been so positive for me, I just thought I’d share my story for others who may want to try it,
It sounds like you eventually settled on a method that works for you, so that’s great! Human bodies and society is so complex, I have no doubt different methods will work for different people…
> If you have a sedentary job, you do not need more than 1200 calories a day and can very easily get your nutrients with just that alone.
That's not really close to true, at all. As someone standing at 180cm, my basal metabolic rate is about ~1,300 calories[0]. That's assuming I weighed 40kg. A healthy weight for me would be considered to be between 60kg and 80kg, which would put my basal metabolic rate at 1,600-1,800kcal.
I am 173cm (5'8.5"), 65kg. I also run three 8km's and two 5km's a week with a 4:20-5:00/km pace. I do this on at or about 1200-1500 calories. And I still have fat. I am not a flat bellied skinny person either.
Totally agreed. You basically digest food better this way, and use the most of your food, good advices (eating when you feel like it, and only how much you need)
People will often turn to a lot of physical exercises when they want to lose weight, but the important part is your food consumption, minimal exercise is of course still a good idea
I'm not a no carb person. I've tried no carb and it's just too hard to get the energy I need for my activity levels (I know it can be done, but I also like to do things I can maintain for years). But, I do think about my carbs. Meals consist of cooked veggies (my trinity is peppers, onions, mushrooms) or standard salad. Then some type of protein like fish or chicken. Carbs I'll add if I think I need them that day. Rice or I'll cut up potatoes and sauté or oven roast with rosemary and a little OO. I'll also graze on something like hummus and raw veggies and mix in some pretzels.
fwiw I've had better success with low carb diets and energy for workouts when in full blown ketosis (as measured by blood meter). Otherwise, you're kind of in energy purgatory if you simply go low carb.
low carb is a good idea for people more sedentary (who commute with a car), in my case I ride a bike almost every day, so I really need glucose/fructose and carb
When I do sports (riding bike every day for at least one hour in mostly anaerobic mode) after not eating for at least 18 hours or so (which I don't do often), I feel like I've got unlimited resources of energy available.
Color me skeptical. In the anaerobic zone you're going to be at something like 90% of max heart rate and getting almost all of your energy from carbohydrate stores. Most people deplete those in less than an hour, especially when fasted.
When I'm following a polarized training program I find I can do the long, slow aerobic workouts just fine when fasted. But when doing high intensity anaerobic intervals I fall apart quickly if I haven't eaten some carbs before.
I must add to this that I'm a bit overweight, since I don't do any upper body training. I have a BMI of 28 with strong muscles in the legs and probably a good heart, but a lot of belly fat. My HRmax is usually a bit below 180, but definitely above 175, so I'm in anaerobic mode at above 145, where 150 to 160 is what I usually aim for, tending towards the lower limit.
My theory is that at this point I'm somehow just taking the energy out of the body fat, but I'm probably very wrong with this assumption.
As a runner I was told that the liver holds about 600 calories of glucose, which would be roughly an hour of exercise. Though the body doesn’t run straight to the egde of zero glucose, I think it alters the fat/glucose ratio during the first hour of exercise and the 50/50 point is about 30 minutes. Obviously very roughly and assuming normal physiology but matches your experience.
The fat/glucose ratio depends on effort intensity and individual physiology. At very low aerobic intensities metabolically healthy people get most of their energy from fat. As intensity increases the mix shifts until you're burning almost 100% glucose and 0% fat near max anaerobic effort. This makes sense because fat metabolism requires more oxygen and you hit a limit on how much oxygen you can pull into your bloodstream. Once stored glucose is depleted then either you need to consume some carbs, or drop the intensity way down. The point at which that happens varies widely based on multiple variables.
As you're on a bike, it would be a lot better to get a power meter, take an FTP test and then ride 20% above your FTP to properly ride in an anaerobic zone. You'll quickly find that long anaerobic exercise isn't possible
Heart rate is too affected by other factors like hydration, temperature, stress etc to be reliable.
Without hills the only way is to ride in a suburban or rural area. You can do 25-30mph safely for miles between lights there which, should be hard enough for most people. Big cities are fundamentally not safe serious athletic cycling, anaerobic or otherwise. At best you spike your heartrate sprinting between lights then stress your body with high HR waiting at a light. Or guys will do near 30mph in a paceline around Central Park and act offended when some tourist steps out in front of them.
A dynamo connected to a resistance will do. An old bike had a dynamo connected to a rechargeable light, the bike felt heavier the more the battery depleted.
Alternatively get a Turbo trainer or rollers with resistance for stationary training. Lots of people love it but it's not for me, though rollers aren't bad but the it gets very hot even outdoors with a fan.
I investigated the dynamo solution, but it turns out that modern dynamos have a large airgap which ensures that you can only get a few watts of energy out of them (so you don't overload the lights).
Find a steep hill and you can pedal as hard as you like without going very fast. But in general there's nothing particularly dangerous about riding fast if you have decent bike handling skills and watch out for traffic.
Not consistently, but around 2/3 of the time. I'm usually on trails where there aren't many people and which I know well, so I can go full speed, which is between 30 and 40, rarely 50 kmh downwards. This is on a MTB with offroad tires, which kind of glues you to the ground.
The lower part of the image contains a red line, which is my heart rate. You can dimly see a green and a red region, where red is anaerobic, the transparent area below it aerobic, the green area fat burning, the area above red is the warning zone above 90%.
The white and green line is the speed, where white is GPS-speed and green is a speed sensor on the wheel. Blue is the pedal cadence, apparently the battery is dying.
Black is GPS altitude, dotted black is barometer and magenta is environment temperature (an ESP32 with a Bosch sensor connected via BLE to the phone).
The first one was Thursday in the morning, because I had my second vaccine that afternoon.
The second one in the late afternoon because I wanted to wait as long as possible because of the vaccine. You can see in the white speed profile that I was doing the bedding-in of new break-pads while going down the hill. This was with another bike where apparently both the speed and the candence sensors are dead.
The third one was a longer ride today where I went up the mountain on the other side (shortly after 5pm) with an average speed of around 7 kmh climbing a height of 170 m. This was a total of 28 km in 1:30 h.
Did you know that fasting for one month a year is obligatory in Islam?
“O you who have believed, decreed upon you is fasting as it was decreed upon those before you that you may become righteous.
Fast a prescribed number of days. But whoever of you is ill or on a journey, then let them fast an equal number of days after Ramaḍân. For those who can only fast with extreme difficulty, compensation can be made by feeding a needy person for every day not fasted. But whoever volunteers to give more, it is better for them. And to fast is better for you, if only you knew.“
- Surah Al-Baqarah 183-184
As far as I know, during Ramadan you're only allowed to eat and drink when it's dark, which is more like a pretty extreme version of intermittent fasting (depending on daylight duration).
yes depending on your daylight, approximately, it takes between 13 and 18 hours. I am fasting one month a year, more than 10 years, and I can’t call extreme, it’s more like need
Ramadan is for one month and you'd be hard pressed to find a lot of obese people seeing as much of the Islamic world is not only still developing or war torn, but also very poor. You would have to do a study of ones closer to normal western standards of a daily diet to get a better control. Otherwise of course the weight of a country where you work 12-16 hours a day and eat 1600 calories max is going to be full of thin, lightweight individuals. The fact that they fast one month out of the year would have no large scale effect. Also, during Ramadan, you can eat/drink before and after sunset/sunrise. So if you gorge, your stomach size increases and then naturally adjusts to the schedule so you whole digestive system sustains itself over a longer period of time as opposed to churning calories as they are incurred.
Edit: my comments on the Islamic world were not a slight. It's a factor that should heavily be taken into consideration when comparing them against Western nations that do not have even remotely the same medical problems in regards to weight.
I can cherry pick places in a set that do not conform to the rule too...
The Arab world is about 423 million people[0]. The places you've referenced are ~41 million people[2][3][4]. 10% that do not conform to the rule is still not the rule.
This does not include other Islamic countries but for the sake of berevity we'll just fact in the whole Islamic world (including Iran, Pakistan, Malaysia, Indonesia, Bangladesh, etc) of 1.8 billion people[1]. Now your subset just went from 10% to ~ < 1.25%. You're argument is absurdly invalidated statistically right there.
>...obese people seeing as much of the Islamic world...
Thanks for cutting of a very important part of my actual statement to paint me as some ignorant moron.
Also, 41 million are not obese. Now your articulating another data point to suit your narrative. I'm talking in the grand scheme. My argument was never "hur dur there aren't obese people in the Islamic world!"
The US alone has 30-45%[0] obesity among 300 million meaning. The Islamic world has 1.8 billion. Assuming we just use the same statistic on the high end of the American side for the three countries you named, that is still only 18 million. The US has 96 million on the low end. If you factor what I actually said, the Islamic world, it's again, an even smaller percentage than the 1.25% I quoted earlier.
There wasn't really a good place to cut the quote, so I trusted people to follow the thread. I have no intent to paint you as anything and don't think a reasonable reader would be convinced you're ignorant from what I replied with.
I have no real narrative to speak of in this conversation either, my only intent was to point out why I thought the great-grand-parent post had included those data points.
People binge on sugary drinks when they break the fast then stay up all night eating meat and rice. This doesn't do good things for insulin resistance.
This study is in rats, and if I'm reading the article correctly it also involves a population of rats that are bred to be predisposed to hypertension. So although it sounds like there are some interesting anecdata stories in the comments, this is very far from being generalisable to human populations. Seems like it would be a pretty easy study to do in humans though, to the point where I wonder if it hasn't been done already, even if not specifically focused on gut bacteria.
Also improve insulin sensitivity, reduce glucose and/or insulin levels, improve lipid profiles, and reduce markers of inflammation and oxidative stress.
Does anyone have any fasting advice from a reputable health authority?
For some reason the NHS doesn't really have any online, even though a sizeable proportion of the population observe Ramadan. They usually have good, well-cited articles on this kind of thing.
Most of the primary research isn't really focused on generating "advice." If I had to pick the protocol with the best direct evidence, I'd pick "early time restricted feeding" (eTRF).
https://pubmed.ncbi.nlm.nih.gov/29754952/
That's what Brian Johnson practices. It's not a fasting protocol I would actually recommend to most people because it's pretty inconvenient, but it's been directly studied as an intervention.
I had a huge drop in blood pressure once I started fasting daily. Even though I lost only a modest amount of weight (approx. 10 pounds; I was never obese, only slightly overweight with BMI cca 27), my blood pressure plummetted from 150/95 with medication to some 115/75 without medication within a month.
This holds even when I no longer fast daily, only a few times a week. Additional Concor, taken against post-Covid arrhythmias, reduced my BP to some 105/70 when relaxed. Going any lower would actually mean a risk of fainting.
This seems to be consistent with the theory of gut microbiota being reshaped. I can also tolerate milk slightly better than before; my tolerance still has limits, but I won't get a rash after a single cappuccino, which I most definitely used to before.