Extended fasting made me gain weight? Why?

(Kiki) #1

Hi there. I need some encouragement on day 4 of an extended fast. I have had nothing but water and black coffee for 4 full days now. I made the mistake of stepping on the scale, only to learn I had gained 4 oz. I went on keto for health reasons 3 years ago and have never, ever cheated since. I have a constant 5lb creep that I always try to bring down or prevent. I know I am at a decent weight, so don’t have much to lose. Keto alone didn’t help me fight the 5lbs, so I added omad 5 days a week. That worked for a few mos, then no longer helped. Then I was told to shake it up, avoid calorie restriction that might be slowing my metabolism. I then started doing extended fasts of 2-4 days. That worked wonderfully for about 6 mos. now shooting for a 5-day and am disheartened by the scale. I am pretty small, so usually weigh around 115, but was up to 119 this morning on an empty stomach. Any advice? Is this fasting and strict Keto a waste for someone like me? I do feel good and have combatted many health issues with Keto and fasting, but keeping my weight down is an important goal for me. I just like to wear and fit my clothes!


I am not endorsing this person as an expert, I have no idea what her background is, but I stumbled upon this video last night and personally found it helpful. So far this is the first resource I have found on my own about no loss/gains when fasting, maybe others here can pitch in with more :blush:

(Michael - When reality fails to meet expectations, the problem is not reality.) #3

You’ve discovered the free lunch. :innocent:

(Bunny) #4

Would never depend on “fasting” to lose weight long-term, it actually encourages re-gain, the more you try to do it the more the weight wants to come back permanently?

You probably need a little more skeletal muscle volume to achieve stability in adipose weight (Resting Energy Expenditure REE) so that will make you weigh more?

Those fluctuations I see in your weight look like water weight gaps to me and look like normal fluctuation gaps for body weight not adipose weight.


How tall are you and do u exercise regularly?

(Kiki) #6

I am 5’5 and have been a life-long athlete. I exercise regularly. I did take it a bit easier during my 4-day fast and only walked 3-4 miles a day because I was so hungry until today. I worked out a lot harder today bc I felt better. The first time I did a 4-day fast, I lost 6-7 lbs, got down to 112 and was able to eat and snack quite a bit for a couple of mos with effortless large ketone levels. It wasn’t until many mos after my biggest fast that the weight creeped back up and my ketones dropped, even though I stayed on strict Keto during my refeeding days. Thanks for asking

(Give me bacon, or give me death.) #7

I suspect that 0.25 lb. is well within the limit of error for your scale and therefore not worth worrying about. I have been fluctuating within the same 10-lb. range for about 18 months, and have learned not to care about the variation, since it has no practical effect whatsoever.

(Robert C) #8

Here is a possible explanation…

A 4-day fast should result in about 2-3 pounds of fat loss for a 5’5 woman (your body can’t and doesn’t want to let go of fat faster than it has to to meet basic energy needs - it won’t “overburn” 7000 calories a day just because you are fasting).
The rest of the change (about 4 pounds) was likely water and changes due to monthly cycle.

This 4-day fast will likely have resulted in about the same 2-3 pounds of fat loss (i.e. you have not eaten anything and did not die so the energy came from somewhere - especially if you were Keto going in so glycogen stores were near 0).
But, approximately the same 4 pounds of water weight change happened to go the other way this time - essentially hiding your fat losses.

(Bob M) #9

As your body performs a long term keto adaptation, your ketones (blood, breath, whatever) will go down. I started taking ketone levels (blood, urine, AND breath) about 1.5 years into low carb/keto, and I’m almost 6 years into it now. I used to get high ketones with no problems, fasting 4.5+ days would get me near/over 5.0 mmol/l. The last time I fasted 4.5 days (and took ketones), I got 1.9 mmol/l. When I was taking my blood ketones, I was commonly below 0.5 in the mornings. Similarly, I could get quite high breath ketones, 70+ at times (using a first version Ketonix). Now, the highest reading I’ve had in several months is a 67, and I’m normally between 20-40. To compare, in October of 2017, the lowest reading I got in a few weeks was a 44, and I was between 57-68 most days. I easily average 20-30 “points” less than that, now.

So, lower ketones don’t tell you anything.

As for fasting 4 days, I know Dr. Fung thinks everyone can do this and there are no negatives, but I wonder. I have been fasting 4.5 years (yes, YEARS) now. I have found fasting to be harder and harder as time goes on. Granted, I’ve lost another 30+ pounds and gained maybe 10+ pounds of muscle since I started fasting, but I wonder if it gets harder and is less important?

For your fast, I would think you would lose some weight, if only because you aren’t eating. If you aren’t eating, there has to be a few pounds right there of food that’s no longer working itself through you. But how do you know your metabolic rate isn’t going down to compensate, particularly if you’re thinner (less energy to get from the fat you have), and are still exercising somewhat during the fast? I used to be able to fast 4.5-5.5 days and exercise during the fast, but now I don’t even attempt to exercise and still have difficulty making it through a fast.

(Cancer Fighting Ketovore :)) #10

Which is it? I assume in the first part of your post you meant to say it was a 4 pound gain, based on the latter part of your post. I can see being worried about a 4lb gain, however. Was this change over 24hours?


In her first post she said she’d had close to an overall 5 lb. gain (sounds like it might just be 4 lbs., but maybe she’s already dropped some of that gain) that she was trying to shake by fasting. During her fast she’s gained .25 lbs.

As to the original question–I’ve gained weight during fasts. It’s irritating to have that happen after all that work, but it does happen. Sometimes I get regain on top of that, sometimes not. Like any other process of losing weight, you really need to look at your overall trend. Yes, I’ve gained during a fast, but I’ve also lost 4-1/2 lbs in two days and had no regain. Neither of those is the norm, but they both contribute to the trend. My personal trend, when I’m really in a groove with two-day fasts, nets out to about 1.2 lbs. for the two days.

(Full Metal KETO AF) #12

You are having completely unrealistic interpretation of your weight gain. 4 ounces is a half cup of water! At 115 probably your body doesn’t want you losing any more weight. You look young enough for me to assume you are still having menstrual cycles, give yourself a break. Your weight will never be stable as long as that’s going on. :cowboy_hat_face:

(Joey) #13

Perhaps I’m mistaken here, but at your weight & height, it sounds like you’re flirting with being underweight (BMI around 18-19?). There’s a chance that when you fast for multiple days like this you are slowing down your metabolism … such that you are compromising your health and making it easier to re-gain the weight when the hunger gets the better of you.

Is there a compelling reason you feel that you are too heavy? Is fitting into those clothes again from long ago a realistic goal for you at this time in your life?

(Kiki) #14

My weight creeped back up to 119, so I started the fast to drop back down to my 112-115 range. After 4 days, I was up four oz, but was bummed I didn’t lose anything at all. I am on 120 hours now and am at 117. I do appreciate all the feedback. It’s good to know that fat adaptation over a long time is not reflected in ketone levels as your body adjusts.

(Kiki) #15

It was the four lb hold/stall with no weight loss after 4 days that bothered me more than the 4 oz gain, but yes. I do need to remember that clothes fitting means more than weight on scale. I am at day 5 right now, almost 120 hours and scale shows a 2lb loss total for 5 days, but clothes are finally a bit looser. I am working out hard today bc I feel good and plan to break my fast tonight with a bun less burger :slight_smile:

(Kiki) #16

I’ve considered that. My BMI is low, even at the high-end weight range. I know it sounds a bit obsessive, but I worry about letting my weight go too far up when it gets harder to lose so much. I come from 2 very obsese parents who fight stage 2 diabetes and so not want to be sedentary and miserable like them! The clothes are unfortunately not from long ago. I usually hover in that size, but fight the constant creep. Fasting used to work like magic and actually seemed to boost my metabolism for mos after doing EF. I hope I am not slowing my metabolism. I am shivering all the time now. Good news is that even though my weight has only dropped 2 lbs on scale after 120 hours of hard EF, my clothes felt a little looser today and that should matter more. Thank you for the response!

(Kiki) #17

I would be delighted if 2-3 lbs of fat dropped each day, even if the scale doesn’t show it! At almost 120 hours, I am 2 lbs down in scale, but I feel pretty good and my clothes fit a lot better. So, thank you for the encouragement! Also good to remember that the ketone levels don’t go as high when you do Keto and fasting for a long time like us.

I feel better after your response. Thank you. I know I am a bit obsessive and I need to chill out and think about that sugar free and no-bun bacon burger that I am going to eat tonight to break my 5-day!

(Cancer Fighting Ketovore :)) #18

OK. Thanks for the clarification. When I read your post I got confused (since both weights had a 4). Plus, keep in mind that a small change like that could simply be how you are standing on the scale, how you are breathing, etc.

This is not a linear process, and not everyone has the same results when doing the same thing. You’ll get to a good weight for you eventually. :slight_smile:

(Kiki) #19

Btw, I also kicked cancer’s butt. Breast cancer and a close call with colon cancer. I am only 46 now. Non cancerous Tumors all over the place too. Hence, my Keto and fasting inspiration. Thanks for replying!

(Cancer Fighting Ketovore :)) #20

You’re welcome!
I’m in the middle of the fight. I’m specifically not trying to lose weight, but instead just fight the tumors and starve them. I’m Stage IV (it was already that advanced at diagnosis), so I’m doing everything I can to starve the cancer, along with the medication I’m on. A small group of people on here are doing keto for cancer related reasons, so our methods and thinking are a bit different from those who are T2D or doing it for weight loss. Just saying it because my views are a bit biased in the cancer-fighting direction!

Congrats on also kicking cancer’s butt!
Feel free to check out my blog www.KetoCancerMom.com to read my full story.