So far I’ve heard only overwhelmingly positive things about IF. What are the downsides?
These 3+ day fasts seem especially dangerous. Vitamin deficiency, malnutrition, hair loss, poor skin health, etc. are all common when we don’t get enough nutrition. How does it make sense that getting 0 nutrition over days has only positive health effects?
If you have a history of gout, fasting can sometimes cause a flare-up. It does for me every time I try fasting. I still do it at times because I love the benefits, but ugh gout is so painful and hardly anyone talks about this. I do see occasional online information about it so I know it’s a thing. Maybe it’s rare? So hopefully most fasters never experience it.
Aside from warnings from your doctor regarding some preexisting condition, there aren’t really any downsides.
I began fasting for cognizant benefits and I found that doing without food during the day, or running after eating to deplete glycogen reserves, makes my mind a lot clearer. I’m sharper and more aware of tasks. Critical thinking and analysis kick into higher gears and I can challenge myself a lot more.
Apparently, challenging your body on so many levels staves of mental decline and may even prevent neurological disease and degeneration. Some cutting edge research even shows how fasting (and other healthy habits) can aid in growing new neurons.
Fasting is incredible and I can’t recommend it enough.
The primary downside is economic.
Businesses which rely on consumers to eat 3 square meals a day, buy snacks in between, drink more milk, buy Girl Scout cookies, never skip breakfast, support your local bake sale… etc. All those groups suffer if people just eat less
The awkward reality is that Americans just have far more food than we know what to do with
Before modern convenience of ample food supplies, people routinely went for days without food and the gorged themselves when food was available ie: after a successful hunt or finding edible grains/fruits. Humans can live 3 days without water and 3 weeks without food on average. A multi day fast does cause your body to change gears but will not harm a healthy individual… just make them hungry. Your body has a pretty good reserve especially if you’re a little overweight.
Your body has fat stores for a reason, so that it can go on living when you don’t have food intake. By not eating for a week or so, you are not going to be malnourished.
No one is gonna become deficient by not eating a few days, unless they had pre-existing deficiency.
Also, no one is stopping you from consuming multivitamins if you so choose during your fast.
Fasting does not cause poor skin, if anything it makes skin way better. It might flare up, due to a pre-existing condition, or due to toxins release. You are probably not consuming enough water, or your kidneys are not working properly.While it is anecdotal, not one person I know has fasted and had it result in poor skin.After day 4 or so, I have noted skin generally looks way better, glowy even.
Longer fasts are the most efficient, effective & fastest way to loose weight.Anyone that says longer fasts are not worth it, says so for one reason and one reason alone.They do not have the mental fortitude for it.
The drawbacks of longer fasts are more along the lines of
You have to consume electrolytes, can’t just stop eating.
Diarrhea if you don’t control your electrolytes.
The hunger pangs before the hunger dies away.
Boredom due to not eating
Insomnia if you are not active enough throughout the day
The mental strength required to not eat, when you see delicious food pop up all over the place.
The average human body only store glycogen for 1,5-2hrs of hard, physical activity. Meanwhile an average normal (non-overweight) human stores more than 80.000kcal energy in fat. As soon as you have depleted your stored glucogen your body will start consuming the, in this sense, endless amount of energy stored. That’s why there’s a lot of truth in the old saying, that a human can “go three weeks without food”. Yep, three weeks at least.
Just get some electrolytes, as you drink a lot of water. It makes everything easier.
One reason is that many metabolic activities turn on during a fast that are normally off. One is scavenging and recycling protein. I am sure there are other bits of house cleaning that are triggered by fasting as well.
In nature it is normal to not eat every day, or even for a few in a row. Some days dinner is faster than you are. We are evolved to deal with it. In fact I would say people do better with fasting than high carbs over the long haul.
If on average you eat enough calories in the week it does not matter too much how you get them from an am I eating enough POV.
Read the obesity code - a three day fast is a lot less scary than diabetes & early death … I’ve done multiple 3-5 day fasts & they are easy for me. I take electrolytes & have no problems. I had a mass on my liver before fasting that they can no longer find. That’s a lot scarier than a vitamin deficiency (our bodies are great at holding on to nutrient strength & our bodies like running off ketones)
I think it varies from person to person. I get horrid migraines even with a ton of electrolyte supplements. The only way I can do extended fasts like 36+ hours is if I literally go get an IV drip and the migraines stay. They don’t pass. I’ve done multiple 3-7 day fasts and the migraines just don’t ease up and I also don’t sleep despite tons of cardio and activity. I also get diarrhea no matter what I do and for the duration of the fast. So…for me it’s no sleep, migraines, and having to be close to a bathroom at all times.
I stay low carb or keto all of the time and it’s not keto flu…I’ve even worked with my doctors on all of the above but more electrolytes make the stomach issue worse But I do them anyways.
Hair loss comes with most quick weight loss. It grows back.
Bad breath is a thing and my focus goes to shit so I just plan as best as I can and I do oil pulling and tongue scraping.
BUT some people just kill it with fasting and some people don’t. I’ve seen other people that keep waiting for the “fasting High” that never comes and that’s ok. We all choose to fast for different reasons But the benefits of fasting outweigh the negatives.
I still love fasting. Calorie control, keto, cardio, lifting, and whatever else just doesn’t work. I HAVE to fast if I ever want to lose weight.
It’s not ideal if you have POTS either bc of the electrolyte and blood pressure.
Anything over 24 hours seems extreme to me. I am currently losing weight via a combination of OMAD and 20-4. I could easily fast for longer than 24 hours, but I don’t think it’s sensible.
I’m losing weight. I feel OK. I just don’t feel any need to starve myself for days at a time. What is the point?
Some people just like to take things to extremes - e.g. vaping insane clouds from ecigs, running seven marathons in seven days, starving themselves for a week at a time. I don’t consider that behaviour normal or something to admire/emulate.
Your body can store a lot more than it needs for 3 days. Those deficiency symptoms are much more long-term neglect.
For me, when I’m having stomach troubles, a short fast is really helpful and generally pretty easy. Gives the stomach, which is basically always working, a chance to heal and reset itself.
Possible negatives like lost fat in your essential organs start creeping in around the 7 day mark. But even that stuff recovers pretty quick once get back to normal eating.
However there are also some risks involved if you had preexisting health conditions with longer fasts so you would want to talk to a doctor in that case.
From what I’ve heard though 7 days is generally safe and beneficial for most people unless you want to gain muscle in that case it would hinder your progress. One of my favorites podcasters, longevity science researcher, Dr Peter Attia switched from 7 day fast once a month to 3 days only because he personally wants to build muscle.
The main downsides are increased stress, hunger and tiredness (these difficulties are exactly what triggers all the positive benefits), and they greatly improves on the third day once your body adapts to the stimulus a bit better. One huge contributor to this is that you lose electrolytes much faster at the beginning of a fast. So if you take electrolytes it helps a lot.
>These 3+ day fasts seem especially dangerous. Vitamin deficiency, malnutrition, hair loss, poor skin health, etc. are all common when we don’t get enough nutrition.
None of this is happening in 3+ days.
It’s not like people who fast don’t eat, they just eat way less and eat more nutritional / better food on refeed.
>How does it make sense that getting 0 nutrition over days has only positive health effects?
That’s how it was for a long long time. Growing stuff took time. Hunting meant food today, and then no food until something was caught which could be days.
It’s more natural than you think.
>These 3+ day fasts seem especially dangerous. Vitamin deficiency, malnutrition, hair loss, poor skin health, etc. are all common when we don’t get enough nutrition
You’d think the human race would have been wiped out by now.
>How does it make sense that getting 0 nutrition over days has only positive health effects?
You are having things backward: it’s eating every single day that doesn’t make sense, we did not evolve with grocery stores down street, and certainly not with sugar jampacked food with no fibers.
Where are you getting you info?! If you don’t believe in fasting why are you here?
Mmm, I am a 66 year old woman. I completed a 120 hour fast using snake juice check r/snakediet. I added periods of dry fasting check r/dryfasting. And I didn’t suffer hair loss. And my skin looks clear.
My rheumatologists and neurologist don’t agree with fasting but my lab results speak volumes to them. I will continue to fast. If others . It’s not my business. I am not here for them. I fast for ME!
I do the extended fasting specifically for the amazing skin results! My face has never glowed this much since I was 20! Even the dark spots are starting to lighten (I’m 44F). The vitamin deficiencies won’t truly be a factor unless you’re fasting for months on end. The body has months of supply and a daily vitamin will ward off most issues. There have been severely obese people who have fasted for a year with nothing but a daily multivitamin and no deficiencies to speak of.
I’ve had huge downsides, but I’m still trying to make it work. I did not consult a doctor, like ever, and so I didn’t know that fasting for women is different than fasting for men. I really messed up my hormones and my cycle and for years I’m having problems with hair loss.
Then started following a doctor on YouTube who talked specifically about fasting for women, and if you don’t stop fasting the week before your period then you can mess up your cycle and lose your hair. So now I just stop fasting the week before my period and it helps, but I definitely gain weight that week and it’s hard to break even and lose the weight during the remaining 3 weeks. I’m a healthy weight now, but I still wanted to lose more.
Possible negatives like lost fat in your essential organs start creeping in around the 7 day mark. But even that stuff recovers pretty quick once get back to normal eating.
However there are also some risks involved if you had preexisting health conditions with longer fasts so you would want to talk to a doctor in that case.
From what I’ve heard though 7 days is generally safe and beneficial for most people unless you want to gain muscle in that case it would hinder your progress. One of my favorites podcasters and longevity science researcher, Dr Peter Attia switched from 7 day fast once a month to 3 days only because he personally wants to build muscle.
The main downsides are increased stress, hunger and tiredness (these difficulties are exactly what triggers all the positive benefits), and they greatly improves on the third day once your body adapts to the stimulus a bit better. One huge contributor to this is that you lose electrolytes much faster at the beginning of a fast. So if you take electrolytes it helps a lot.
Another big factor to the difficulty of longer fasts is how adapted your body is at switching to burning fat. So it helps to build up to longer fasts with intermittent fasting or switching between 24 hours fast, 24 hours eating for example. Also peter Attia will eat keto the week before and after a long fast.
Did a 100 hr fast once and multiple 3 day fasts as well.It’s a beautiful thing, I didn’t really feel hunger or any kind of physical weakness. The only issue was social, especially the keto breath. But there are ways around that too.
It’s a high but you gotta build it hour by hour.
For me I can’t workout fasted some can I can’t. I have to eat half my meal before then eat the rest after so I dont feel sick to my stomach and get light headed. I can do like push ups and light stuff at home, but I can’t lift weights fasted within 30 min it’s over. I also have to plan things out more for my life. I’m flexible with how long I fast but it’s something extra I have to think of each day. Like what am I doing tomorrow, I’m going out to eat with my gf so I need to fast more today so tomorrow my eating time is around that time, you do get used to it though. I also can’t do any off days if I do I get horrible acid reflux for some reason and I feel horrible the next day on top of that. Other than that the first 2 weeks getting used to you’re very hungry lol. I feel the positives way outweigh any negatives though.
For a person of normal weight, fasting can be dangerous. For an obese person (which I’m assuming is the reason most of us are here), fasting helps stave off the hundreds of other more serious illnesses that come with obesity.
I do a 16:8 IF and I’ve only done a 24hr fast a time or two and so far it’s just meh.
The negative is I’m hungry (obviously), the positive is after 17 hours or so my mental clarity and self awareness rises a bunch. Not sure why.
I have cognitive difficultly the further I go- concentration, critical thinking, focus and feeling generally sleepy. It feels similar to when I was a sleep deprived new mom of twins. Most people seem to use coffee to counter that, however I don’t t tolerate caffeine so your millage may vary…
That said - upon eating, it resolves within 20-30 min, so it doesn’t feel ‘risky’. I truly do INTERMITTENT For that reason - some work days need razor focus and others are just mouse clicking. If I’m struggling I just cut short and eat.
My general sense is that this is ONE Tool that aids weight loss. I combine it with other tools too to arrive at something manageable. Personally I’ve found it really helpful - mentally it’s easier; hunger is better controlled; food more enjoyable - also as someone who’s very busy, it takes something off my plate (literally! Ha!)- mornings are faster and 21 meals worth of cook I don’t do and of dishes that I don’t wash :)
My first fast was for a routine colonoscopy- that was the moment I thought “this really isn’t that big a deal” after really dreading it for MONTHS!
This guy went over a year with medical supervision and fasted with 0 negative side effects. She does a good job explaining mechanisms that we have built in to handle long times between meals.