48 hours, 72 hours or even longer fasts. What benefits will be had?

(Keto life n' a little hippie ) #1

So I’ve done fasting two times now. First was 72 hours. Last 12 was a bit painful, I woke up and couldn’t sleep more that night because I was so hungry. But I stuck to it and completed 72 hours.

This weekend I did 48 hours fast. Much smoother, less stressful and I slept like a baby.

Could be that I knew what to expect and was more mentally aware when the first hunger signals hit my brain so I could keep busy and avoid get stuck cultivating the hunger pain. Or it could be 48 hours is just that much easier because of the shorter fast. I also do IF on a 18/6 or 20/4 routine depending on schedule, whats in my calendar and what I need to get done.

Anyway. Before I fasted I read up and took notes to get a better undersatnding of how and why I should fast and all the benefits from fasting. And I felt like all those benefits from fasting, it was like everything that is missing, or what I’ve been short changed for in my life. So I think I can have huge gain from fasting.

For a short period until first week of august I will do fast once a week. At the moment I lean towards the 48 hours fast, because that was easy. But, at the same time, I need to harvest as much of the benefits from fasting before I head of to fat camp in august. It is a 6 week course with insane exercise program, tailor’d to each individual, of course. But still, after years on the office chair and in the coach at home the longest walks I’ve done is the walk from an airplane to the baggage pick up point. Or from the door to the car at the parking lot.

My fear is the my weight already high markers for inflammation will cause joint and back pain soon after I put my body to work. And I need to do what I can to compensate. And fasting is the only thing that might give me a boost I feel. If I can manage I might even do a weekly 48 hours at the camp as well.

So for stam cells, autophagy and to lesson inflammation, will 48 hours work well, or should I just bite the bullet and do 72 hours fast?

I’ll read somewhere (didn’t seem to bookmark it) that there is a diminishing return from fast over 72 hours. But some sites said even 48 hours. And that stam cells are already renewed after 48 hours fast.

What is correct, will 48 hour fast suffice or should I do 72 hours fast to get the most benefits?

I can manage both, I know that. But I would prefer not withdraw all my willpower before I enter the camp. I should keep enough in the bank for a few withdraws at the camp too, because that will most likely be the toughest and hardest thing I have ever done.

Prolonged fasting 72 hours?
(Jane) #2

Unfortunately there is very little data on human studies about autophagy because there is NO MONEY to be made when people simply DON’T EAT.

The thing about fasting is you can stop at any time. I’ve done 36 hour fasts and I’ve done some over 100 hours. For me… they don’t get harder the longer I fast but some fasts are definitely much harder than others. I stopped one at less than 8 hours once!

You can set a goal of 48 and see how you feel. If ok - then try to go for 72. The only issue I would have with that is once I’ve set my fasting “goal” I tend to get hungry when it gets close to time to break it. If I tell myself I have another day before I can eat it is easier to ignore the hunger waves.

Everyone is motivted differently so you have tgo find what works for you. 48 hours every week is great! Better than no fasting.


Megan Ramos talks about how you build up a “fasting muscle”, meaning that they get easier as you keep doing them. I highly recommend reading Jason Fung’s books, or his blogs, or watching his videos on YouTube to learn more. There are lots of Megan Ramos videos on YouTube as well.

Congrats on your first fasts. You are doing terrific and I’m cheering you on!! :heart_eyes_cat::man_dancing::boom:

(Carol) #4

This. I have seen info from people I respect say 48 hours kicks off autophagy, at 72 hours it generally peaks and holds steady for many more days. That’s what I’ve seen but, who really knows?

I like 72 hours up to 5 days because I love the light and energetic feeling that I get and mentally I think I might be doing the body some good. But, I may end a fast at any time because I know I can do it again whenever I choose. It does get easier when that fasting muscle Megan talks about is developed. Good luck!

(Susan) #5

This might be really exhausting and difficult with all the rigourous exercising they are going to put you through? My advice would be to try fasting there if you can, but if you are too hungry, feel too weak, etc. then stop the fast. That would be what I would do myself at least. Good luck with it if you attempt it there, but just remember not to make yourself too worn out or weak while you are there too =).

(Katie Moe) #6

Ok. I mean absolutely no disrespect on any level, I’m just curious - because I see people doing these extended fasting periods quite frequently - how does this not slide into an eating disorder? Just wondering.


I’m not sure how you can confuse the two? Eating disorders are dangerous psychological conditions. Fasting is therapeutic. There is no causal relationship. This is a quick primer if you want to start learning about the many benefits of fasting.

(Jane) #8

I guess it would depend on what you consider an eating disorder. For myself, I fast for autophagy 1-3 days at a time and I eat normal keto when not fasting.

I suppose if one was always binging and using fasting to compensate that could be considered an eating disorder. I would find that too painful to do as I need to be in ketosis and fat-adapted to comfortably fast for 3 days.

(Keto life n' a little hippie ) #9

I’ve saw that too, but couldn’t find back to it. Oh well, I guess there is the answer right there. 72 hours it is then. Then I can gradually try to occasionally add another day or two as I learn to master 72 hours.

When the body is in a better and healthier state I most likely will ease down on the fasting. Maybe do once a month or every other month. Or who knows, maybe I get hooked and keep doing fast in a steady rhythm :smiley:

(Keto life n' a little hippie ) #10

Eating disorder? Well I lived with two eating disorders for a few decades now. It is called over eating and emotional eating. The keto alone seems to make things much easier, and it also remove the dreaded cravings I used to get. Cravings so intense I couldn’t control myself and would cave in and end up stuffing myself with anything I craved.

If keto and fasting give me a better life I think I happily trade in the two eating disorders I already got for a new fasting one :smiley:

To end on a serious note, fasting does not have to be an eating disorder, it could be a therapeutic way to rejuvenate the body, all the way down to the core cells, to have new stem cells thrive and blossom, as a way to remove inflammation in the body, and to stay healthy even as our body ages.

And fasting combined with healthy keto eating in the feasting period I really think can be sustainable long time.

(Katie Moe) #11

As mentioned, I truly meant no disrespect to anyone. I was just seeking to understand. I have seen people do extended fasts as frequently as once a week and then some fasts get longer and longer for some people. I was just wondering.

Perhaps my thinking is skewed a bit as I have known someone who was on the with-holding side of an eating disorder and it seem to begin with short fasts and then extended fasting that just got more and more frequent and overly controlled.

But really, I was more just wondering if it was a slippery slope or not. Not saying it is, just wondering. I certainly respect each person’s decision to know and decide what is healthy for them.

(Jane) #12

I think you make a valid point. A lot of folks come to keto with a past of eating disorders and while it can help to overcome the cravings and intense hunger that can drive it like @idunno said… I’ve seen some on here that definitely slipped into old eating disorder patterns on keto. I’ve even seen a couple of posts here from folks who were NOT going to fast because they were afraid of just what you said - slippery slope into past habits of eating disorders.

And then you have the occasional desperate post - I am going to fast until all my excess fat is gone instead of eating a sensible, healthy keto diet because it is easier for them to not eat than change their eating habits. Not one person has ever succeeded on this forum who has posted that (so far). I’ve seen some kick start keto with a fast and I see nothing wrong with that if you can manage. it.

(Susan) #13

I have a bad history of eating disorders, both anorexia and bulimia, so I understand your concern. I am also currently on a 72 hour fast (just past the 48 hour mark) but I am not anorexic this time around. I used to binge and then force myself to to throw up, and take tons and tons of laxatives; which could be why I am having so much constipation with Keto (I did too much damage to myself during those years).

My body it still in repair mode though, I have a lot of fat to lose, and the reason I am doing a 72 hour fast is to have my body in Autophagy (which has many benefits). I was on a stall, so this will reset me, and I have been in tremendous pain in my legs, knees and back since doing a lot (for me) walking last Thursday.

I will eat a very healthy Keto dinner tomorrow night at 6pm though, and will not take pills to get rid of it, or throw it up afterwards – and I will not pig out to the point my tummy feels that it is going to burst either… therein for me lies some of the differences. Other differences are I was 88 pounds at 20 (my lowest point for that age) and I thought I was fat…I am 54 now and have learned a lot, the hard way.


I think an eating disorder is as common with 3 or more meals a day as 1 or less. The distinction, I believe, is where you are coming from mentally and emotionally. What is your relationship with your body and food. What is your motives for fasting.

When the fasting is connected to destructive emotional states and an unhealthy life style, or when the fasting is a compulsion it may be connected to an eating disorder, which is an entirely different animal than fasting itself.

Fasting in itself, when used as a tool by someone mentally healthy, is unlikely to cause an eating disorder. Same goes for exercise. HIIT doesn’t cause body dysmorphia just because most people don’t do it. When someone has a pre-existing eating disorder or body dysmorphic disorder it would be wise to be careful and mindful about how to do more radical eating or exercise interventions.

By the way. Couldn’t eating SAD, 3 times a day + snacks 3 times a day, and craving sugar be classified as a type of eating disorder from an evolutionary perspective even though it is considered “normal” in the modernised world today? (Just a side thought)

(Not a cow) #15

Do what you can, I did a 48 each of the last two weeks, this week I am doing every other day which I break at around 2pm the following day, so 42 hour, and next week I’ll try the 72 hour. So far I prefer the 48 hour because it’s done and over with, where the ADF is every other freaking day. ;). I have good food in the fridge to eat, and I don’t like to miss my meal every other day. :), I was thinking I saw that autophagy starts after 24 hours in a keto adapted person, so there are many different thoughts on this out there. I’m doing it for the weight loss right now, brain power can come later. Good Luck idunno.

(Not a cow) #16

This is a great reference that you provided, @andesite, I will save that and use it for friends or family who have some concern about any fasting I do.