Trouble Fasting Beyond 60 Hours

(Tammy) #1

I have trouble fasting longer than 60 hours, which I find strange since the common wisdom is that the first two days of a fast is the hardest and that hunger is greatly diminished once you get over that hump. I can fast for 36 hours quite easily, 60 hours is not too bad. I get hungry a couple of hours before bedtime, but it is tolerable. I have only managed to fast for 72 hours once and that was strictly through force of will, I was soooo hungry the last evening of the fast. Aside from the hunger, I felt fine.

_Background: Iā€™ve been on Keto for 13 months, lost 65 lbs, goal is another 25 pounds. I started doing 36 hour fasts most weeks after 4-5 month on Keto. Occasionally, extending it to 60 hours. I do have a cup coffee when I fast sometimes with 1 TBLS of butter, sometimes black. I also drink Ketoaid that really made 60 hour fast much easier.

Any idea why I might feel so much hunger at 60 hours of fasting and how I might be able to improve it. I thought I could work my way up to an 84 to 96 fast, but Iā€™ve hit a wall. I would love to be able to do an occasional 3 or 4 day fast for the benefits of autophagy.

(Raj Seth) #2

If you read Jason/Megan blog at idmprogram.com, they find that ADF - alternate day fasting - which is a series of 2-3 36 hr fasts weekly, just about the most effective on almost all fronts.
You say 36 hours are easy for you - well then - you are on easy street!!
Stay with 3 x 36 hr fasts a week. e.g. f donā€™t eat Monday, Wednesday, Friday, and feast other days - or whatever suits your scheduleā€¦

(Bob M) #3

You donā€™t have to fast that long, in fact Megan Ramos (works with Dr. Fung) often has people doing 36 hour fasts 1-3 times per week.

Autophagy is a different story. I have not seen clear guidance about when this starts. Some believe the glucose-ketone index explains it, but for me to get into the values necessary there, I have to fast many days (4+) in a row. Otherwise, my blood sugar is too high and ketones too low.

When I started fasting 2.5+ years ago, I could fast 4.5-5.5 days with no problems. And I used to exercise several times while fasting that long. Iā€™m thinner and more in shape (more muscle) now, though still overweight. Iā€™m finding it difficult to fast 4.5 days now. I did one last November, but only made it 3 days this January. I am back to fasting 36 hours though, trying for 2 days/week.

(Bob M) #4

Oh yeah, and if Iā€™m fasting 4.5 days, I donā€™t attempt to exercise during that time. Now, exercise causes me extreme hunger. So, I fast 36 hours, go to the gym at the end of that time, eat a few hours after exercising.

(Doug) #5

Around 18 hours is a tough time for many, and feeling that day #2 is the worst is pretty common, too. Iā€™e found that I never know how a fast will go, even as theyā€™ve gotten easier and better the more I do them, overall. I quite 2 fasts after 3 days fairly recently, having planned to go longer. Just was not feeling it - not with dire hunger but just a ā€˜wanting to eatā€™ thing that was distracting.

Then, 2 weeks ago did a 5.5 day fast - the easiest ever, felt great all the way through. I think to an extent itā€™s a roll of the dice.

If you have only 25 pounds to lose, your total fat stores are only so big, and thereā€™s a limit to how much energy can be supplied by every pound of fat, per day. Your body may really be feeling a shortfall in energy after all the liver and muscle glycogen is depleted - this takes some people a couple days. Mostly, the less fat we have, the tougher extended fasting gets to be; very common experience.

(Tammy) #6

I understand that as my fat stores decrease it may become more difficult for me to fast. But even at 50 lbs over my goal (which isnā€™t particularly low) I had trouble fasting over 60 hours. At this point, I should still have about 55 lbs of fat to draw from, which should be enough.

Yes, sometimes even a 36 hour fast doesnā€™t come easy, then I just skip it for a week or two and try again and all is fine. Guess Iā€™ll just keep trying, maybe at some point Iā€™ll win at the roll of the dice and be able to do a longer fast. Was just wondering if there was anything that might increase my chances.

(Tammy) #7

Thanks Rajseth, at your suggestion, I checked out a couple of Meganā€™s blog post about women and fasting. I see that she does recommend 36 to 42 hour fast, three times a week. Though the focus was on fat loss, rather than autophagy. More frequent shorter fasts might be a good alternative since Iā€™m having trouble with longer fasts.

(Doug) #8

Good analysis, Tammy. It can be a complex thing - the mix of available energy, fat-adaptation (you should be fine, there), the varied hormonal influences, etc. While 60 hours is fairly long to just have really depleted yourself of glycogen - especially coming off a keto diet - I wonder what is happening. Ghrelin building to a peak, then?

(Bob M) #9

Why the emphasis on autophagy?

See the following:

Autophagy is also achievable through intermittent fasting just as easily as longer fasts. Autophagy begins when liver glycogen is depleted, around 12-16 hours into a fast. The rate of autophagy peaks there, and then drops after about 2 days. If your goal is a ā€œspring cleaningā€ for your cells, intermittent fasting may be even more effective, since you spend more time in the ā€œearly fastingā€ period when autophagy is at its peak.

From:

Though this also states the following, which Iā€™ve never heard before:

Even fasts of a few weeks or less can have dangerous consequences. Fasting puts two different types of stress on your heart. First, it cannibalizes cardiac muscle for fuel. The human body does everything it can to conserve muscle during a fast, but inevitably some muscle will be sacrificed at the beginning of the fast. After a few days, the body switches over to using fat, but researchers have discovered that protein (muscle) utilization actually increases again later on, even though fat stores are still available. This protein includes the muscle in your heart: weaken this too much, and heart failure will result.

#10

24, 48, 72, 96 ā€” these are the hours toughest for me. They also happen to fall in the middle of my normal eating hours 5:30 to 7:30 pm. When I get a couple of hours past those danger zones I usually do well with hunger.

Right now Iā€™ m coming up on fasting hour 78 and just now getting over a little rough spot. Should be OK until late morning at hour 90 when I plan to end this current fast.

I have to watch my heart (age 68 and heart attack 15 years ago) so I donā€™t like to push beyond the 72-90 range even though I went my personal record 120 hours last week. But it benefitted me no better than my 72-90s in the past. Indeed, I tend to want to feast a bit too much if I go longer.

(Windmill Tilter) #11

Iā€™m not an expert by any stretch, but if youā€™ve lost 65lbs in 13 months, youā€™ve probably been under continuous calorie restriction that whole time. Your metabolism might be pretty darn worn out after all that. If you only have 25lbs of fat left until your goal weight, itā€™s not impossible that your metabolism is yelling at you ā€œwe barely have any fat left here, and you canā€™t have it!ā€.

When Iā€™m going to fast for 4-5 days, I always eat a decent surplus of calories for two days before I start. My TDEE is ~2500kcal, but before a longer fast Iā€™ll eat ~3000 for a couple days. My metabolism seems to appreciate that, and the fasting is pretty easy. When I try to go from calorie restriction straight into fasting, my body wants no part of it. More flies with honey and that jazz (maybe the keto version is ā€œmore flies with baconā€?)

If you want to take another go at a longer fast, it might be worth a shot to try upping your calories 20% above maintenance for a few days prior. Otherwise, doing multiple shorter fasts make a lot of sense.

Good luck and congrats on the great progress!