I am a huge advocate of fasting. There are, however, side effects. Below, I’m going to enumerate a list of seven side effects of fasting. The side effects may be different for others, but these are the most common ones for me, and I am listing them in the order of importance. Number one is the biggest problem, number seven is the smallest problem. As I said, your mileage may vary, but these are things that are common problems for me when fasting.
The Seven Side Effects
1. Can’t Sleep
To me, the largest fasting issue is my inability to sleep. From what I read in different groups and on web pages, and I see in videos, this is quite a common side effect.
One of the great things about fasting is that it really boosts your mind power, and you experience great levels of mental clarity. Because of this mental clarity and mind power, I find it difficult to sleep. My mind is so overactive that I am constantly thinking of new ideas, thinking of ways that I can improve things, and so on.
I love the mental clarity and the mind power, but when it comes time to go to bed, these are a huge factor in making it hard for me to sleep. In fact, as I write this, I had gone to bed about two hours ago and was unable to sleep. Because of my inability to sleep, I decided to get up and write this article. So, as you can see I am experiencing trouble sleeping right now!
Last year, 2017, when I did a lot of fasting (about 200 days during the year) I experienced issues with diarrhea. Usually, I found that around the end of day two until the early part of day three I needed to stay close to the bathroom. Luckily, for me this is not an issue because I’m self-employed, in my office is in my house. Also, I usually stay home, I don’t go out that often. I guess you would say that I’m a homebody. So, during those times I would just need to keep in mind that I should watch out for signs that I may need to quickly go to the bathroom.
In addition to the time that I outlined above, at the time that I would break the fast and start eating again, I would usually experience diarrhea.
Funny thing is, I took about six months off fasting, with a few shorter fasts mixed in, and now that I got back to doing some serious fasting, I am finding that I am no longer experiencing this diarrhea. I think that I had it for because I had been doing so much fasting. It is hard to say, but we will see as I continue doing fasts for the next few months. I expect that within a few months I’m going to reach my goal weight, so I won’t be doing as much fasting this year as I did last year. I do intend to keep fasting even after our reach my goal weight, but not the long duration fasts that I have been used too.
Well, this one might seem like it’s out of place since #two was that I would experience diarrhea. But, yes, this is correct, I would experience diarrhea, and I would also experience extreme constipation.
For example, at the end of my second day of fasting I would have diarrhea, but starting by the middle of my third day it would switch to constipation. And, I mean extreme constipation. I’m not going to go into graphic detail here, but just believe me, it was a problem.
At the time that I took a break from fasting, starting in November 2017, I was even at the point that I would experience the same degree of extreme constipation while I was not fasting. Thankfully, taking that six-month break kind of reset my system and I am no longer experiencing this problem even now while I am fasting. We will see if this reoccurs as I continue fasting this year, though.
4. Want to overeat when finished
I have always found that after the first or second day of fasting I really did not experience hunger. There were times that I thought I was hungry, but if I really thought about it I realized that it was only my mind playing games with me and trying to get me to eat. After realizing this, I could easily put those thoughts aside and not eat.
However, the problem that I did experience in the past was that when my mind new that it was timed in the fast (I usually had a pre-scheduled date for the end of the fast), I would really want to gorge. The good news is that when I did eat, even if I did overeat, I ate healthy things, and only ketogenic friendly foods. So, if I did overeat, it really did not have a big effect on me.
I did worry, however, that if I continued to gorge at the end of my fast I might find the temptation to eat things that I should not eat. Thankfully, this never really did happen, though.
This year, as I have gotten into fasting, I have not found the desire to binge or gorge myself with food. I’m very thankful for that. Perhaps I could say that I am more mature in fasting now.
5. Overestimating Goals
While fasting, I have always found that after the second day or so the mental clarity kicks in, and I feel great. When I’m feeling so great, I find that I start thinking that I could go on for long periods of time with fasting. I’m not talking about thinking I can go 10 days or something like that, I do that regularly. I’m talking about thinking that I could go for six months or something like that, and really believe it because I feel so good. But, things would always catch up with me and I would realize later that it was time to end the fast.
After a couple days of fasting when I start thinking things like this, I am now very cautious to reset my goals, because I know that things may change.
Right now, I am in the middle of day 21 of my current fast, which is longer than any other extended fast that I have done. Funny thing is, I really do feel that I can go on for much longer than my intended 30 days. Right now, I’m just playing that by ear, pondering about going on 60 days, but also comfortable that I can in this fast at any time that I desire. I have already experienced great success, so I’m not worried if I decide to stop even if it is before my 30-day goal.
6. Criticism and Ridicule
One of the hardest things about fasting and something that leads to great pain is that you get criticism and ridicule from many people. I have been told that I’m stupid for fasting. I have been told by close friends that I am an idiot. I have been told many other things along those lines. I had a doctor that told me I was going to die at any time. Even though I know that these things are untrue, it is still hurtful to hear those kinds of things. I have made great strides in improving my health, and even my doctors tell me that while at the same time telling me that I should not fast. It doesn’t make sense.
So, if you’re going to do fasting, especially long-term fasting, you need to develop a thick skin. You need to let that negative talk slide off of you and not worry about it. That is something I have developed over the past year, but when you first started happening it was very difficult for me.
7. Large Gain post fast
After you finish fasting, you do gain a fair amount of weight back. Remember, when you first start fasting you also lose a lot of weight, but that weight loss at the beginning is mostly water weight that you are losing. When you start eating again, your body starts retaining water again, so this weight comes back. The good news is when you start fasting again that weight goes away in a day or two.
One way that I have found that I can avoid this large gain of weight is that I usually only eat one day between fasts, and I avoid almost all carbs. In many cases, I actually eat only one meal between fasts. When I do that, I find that even on the day that I eat I still lose weight. However, if you do a full day of eating, or you do several days of eating, it would not be uncommon to gain, say 5 to 8 pounds during that time. But, remember, as I said, when you start fasting again you may lose 5 to 8 pounds within one or two days.
I have seen many people post in fasting groups saying that they are going to stop fasting because they basically gain everything back when they start eating. This might be the case if you are doing a short fast of maybe two or three days and then eating for the same time period or longer. But, I find if you are doing longer fasts, this simply is not the case.
Wrapping It Up
Well, that wraps up my experiences with negative side effects. Let me be clear, the positive side of fasting is so much greater than these negatives, it is not even a consideration to stop fasting. As I have said many times, I will continue fasting for the rest of my life, not as a means of weight loss, because I expect to be reaching my goal weight within a relatively short time, rather as a means of remaining in good health, maintaining my goal weight, and just generally feeling good.
Good luck to you with your fasting. For those of you who have never tried fasting, give it a shot, I think you might be –
Numbers 1 and 2 have been a problem for me as well. In fact, I agree with all the points. Great job, Bob!
Hi Jason. Hope you are moving forward well on your fast! Today should be your last day, right? Hopefully the problems are small compared to the benefits!
Hi Bob, you’re doing great. I have experienced severe constipation last year whilst taking a course of very strong antibiotics. I tried every remedy the Pharmacist could offer. I ended up by sitting in a bowl of hot water for a couple of hours. It worked a treat. Never had constipation before that and not since.
Hi Norman. Thank you!
Interesting, I never heard of sitting a bowl of hot water! If I experience constipation again I will have to remember that!