Fasting lowers blood pressure by reshaping the gut microbiota
sciencedaily.com
sciencedaily.com
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.
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.
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".
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.
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
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.
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…
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.
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.
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.
In your case, you're fat cells listen to the insulin and you gain weight.
In your wife's case, her blood sugar probably runs higher as her fat cells aren't taking the excess.
Getting fat acts as a sort of protection. You may be overweight, but healthier than a thin person eating junk.
There’s also the fat distribution question. I often wonder about differences in visceral fat.
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?
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
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!
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.
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.
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.
It is rare that eating after fasting causes critical illness. Just check online. People do this stuff all the time.
https://www.hopkinsmedicine.org/gim/_pdf/consult/refeeding_s...
Most Americans could go weeks without eating, and they'd be mostly fine.
Sudden refeeding is an issue, of course, because of electrolyte balance.
But we have a misunderstanding of how long the body can go without food, by design.
What we mainly need is water during periods without food.
After about 3 days without food, the body stops telling you your hungry and switches to fat metabolism.
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.)
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.)
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 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.
I avoid sweets though.
I leaned up which was fine, but I've had to add some grazing in to stay at my goal weight.
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.
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…
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.
Not everyone can be 5'3".
[0]: according to the revised Harris-Benedict
No, its pretty much what a young adult male of median height [0] and ideal weight for height [1] and sedentary, not active, lifestyle needs [2].
[0] 5'9"; https://www.healthline.com/health/average-height-for-men#:~:....
[1] 145 lbs is the center of the normal range for 5'9"; https://www.medicalnewstoday.com/articles/323446#body-mass-i...
[2] https://www.calculator.net/bmr-calculator.html?ctype=standar...
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've been looking for a device that makes pedaling heavier if activated but haven't found it yet.
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.
These are the last 3 days https://imgur.com/a/MG7AlOw
Top is Thursday, middle Friday, bottom Saturday.
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.
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.
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.
I once did a 6 mile hike in (and up) weekend camping trip with just some salt for electrolytes and a pack of hotdogs.
Heart rate is too affected by other factors like hydration, temperature, stress etc to be reliable.
Just a word of caution about this study: it’s still only an animal model (rats). Should be added to the title for clarity.
Which does seem to make me feel a lot beter il have to experiment with fasting as well.
“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
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.
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.
[0]https://en.wikipedia.org/wiki/Arab_world
[1]https://en.wikipedia.org/wiki/Muslim_world
[2]https://en.wikipedia.org/wiki/Saudi_Arabia
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.
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.
https://pubmed.ncbi.nlm.nih.gov/29754952/ https://pubmed.ncbi.nlm.nih.gov/28202779/ https://pubmed.ncbi.nlm.nih.gov/19793855/
Also improve insulin sensitivity, reduce glucose and/or insulin levels, improve lipid profiles, and reduce markers of inflammation and oxidative stress.
https://pubmed.ncbi.nlm.nih.gov/23408502/ https://pubmed.ncbi.nlm.nih.gov/27833048/ https://pubmed.ncbi.nlm.nih.gov/27569118/ https://pubmed.ncbi.nlm.nih.gov/23497604/ https://pubmed.ncbi.nlm.nih.gov/16051710/ https://pubmed.ncbi.nlm.nih.gov/23591120/ https://pubmed.ncbi.nlm.nih.gov/20921964/ https://pubmed.ncbi.nlm.nih.gov/27233359/ https://pubmed.ncbi.nlm.nih.gov/15833943/ https://pubmed.ncbi.nlm.nih.gov/15640462/ https://pubmed.ncbi.nlm.nih.gov/28035343/ https://pubmed.ncbi.nlm.nih.gov/25251676/ https://pubmed.ncbi.nlm.nih.gov/17291990/ https://pubmed.ncbi.nlm.nih.gov/22889512/ https://pubmed.ncbi.nlm.nih.gov/29258678/ https://pubmed.ncbi.nlm.nih.gov/25546413/
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.
They used to even claim fasting was terribly unhealthy.
I wrote this, most of the links are to primary research on fasting.
https://usetemper.com/learn/metabolic-fitness-no-bigger-oppo...
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.