Day 1.
So today, Monday July 18th, I am beginning my first foray into the dietary realm of fasting. I guess technically it began the previous night, Sunday night, as my last food intake was around 9:45pm on Sunday evening.
Now, this is different from my intermittent fasting, in that’s it’s not going to be intermittent. Also, it’s not technically my first foray into fasting as I have fasted before for the fund raising event the “40 Hour Famine”. For his fast though, assuming all goes well, I will be attempting to approximately double the previous time of fasting in the 40 Hour Famine by aiming for something around 3 to 4 days of fasting. I am planning on not eating again until lunch time on Thursday, so that will give me a total of around 87 hours or so of fasting, assuming I have my lunch on Thursday at the usual time of around 1pm. And assuming that I make it to Thursday.
There is a scientific evidence supporting fasting for extended periods of times of 3+ days in length. It does have positive health benefits for you to periodically go on a long fast, similar to the positive health benefits of intermittent fasting, though total fasting is clearly very different to intermittent fasting.
A few other caveats to my current exploration into fasting. I will continue to allow myself to drink coffee and tea, and, as I usually do, this will include milk or half and half in my coffee and tea. I estimate that I will probably be taking in maybe 200 calories per day from the added milk and half and half to these beverages. Other than that I will not be taking in any other calories. I will also be recording my fasting (do I need to say that?) blood glucose levels as well as my fasting blood ketone levels over the course of my fasting. I will record the results once a day, each mid-morning, prior to consuming my first coffee of the day. I will be using the blood glucose and ketone meter described here.
Monday, approximately 10:45 am, my fasting blood glucose level was 89 and my fasting blood ketone level was 0.2. The levels are my usual levels, as is to be expected given that by this time I am doing nothing different than I would normally be doing on my intermittent fasting diet that I have been on for the last few years. I feel fine, at the moment.
Day 2.
Ok, wow. So it’s sort of day 2, though more precisely it’s 36 hrs since I last ate. Monday was day 1 as going for 16 hrs without eating is my “normal” mode, so the fasting really didn’t take effect until I skipped lunch and then dinner on Monday. I am now 20hrs past my “normal” fasting mode. I am feeling super lethargic this morning. It’s very similar to the feeling that I had when I was on a ketogenic (super low carb) diet for 30 days, though it is definitely more pronounced. This is to be expected I guess and is a result of me exhausting the glucose stores in my body and not replenishing
them. I also believe it’s probably because my body is not yet efficiently utilizing fat stores to replace the energy I am not receiving through eating. I will be interested to see what my fasting blood glucose and ketone levels are.
My bike ride into work this morning was certainly very slow and very measured. I had to pace myself and make sure I didn’t fall off or something. I felt low enough that I did almost consider walking and taking the shuttle. Perhaps that will be tomorrow. The lethargic feeling is significant enough that I now understand why people may not make it beyond 36 to 48 hrs of fasting very often. It’s tough and I want to eat. I want to eat less because I actually feel super hungry and more because I just want to feel like I have energy. I feel that I will be able to make it through today but I have a strong urge to end it tomorrow evening, to try and make 72 hrs and then call it. At the moment I am not sure I will make it to day 4 lunch.
My day 2 results of the blood testing was very interesting. My blood glucose was 72 mg/dL, which probably explains the feelings of lethargy and some light-headedness, and my blood ketone level was 2.5 mmol/L. I am well and truly into a ketotic state, producing a relatively high level of ketones. I am obviously not sure, as I did not have the blood testing device when I was doing my ketogenic diet, but it is possible that I did not reach those levels of ketones even after a month of being on a ketogenic diet. If nothing else, it is clear that doing even a short term fast is a really good way for me to kick start a ketogenic state, assuming being in a ketogenic state is something I want to revisit in the future. I’m keen to see what tomorrow brings.
I do feel a little better as the afternoon was worn on.
Day 3.
Hmmm … so day 3 or more specifically, hour 60+. Doesn’t have the “wow” factor of day 2 but that is largely due to the fact that I’m feeling largely the same as day 2. I know how bad I’m meant to feel. I guess, to be more accurate, I’m actually feeling a little different from day 2. More tired but feeling less light headed. Physically, I may actually be feeling slightly worse. The lethargy is still strong in this one. Mentally speaking I am a little better than day 2. I think the physical lethargy is what is making me feel more tired (go figure) so that is why I think, mentally, I am a little better than day 2. Interestingly? Maybe not interestingly at all? The lethargy is also making me sleep well. Even though I am hungry and feeling out of sorts I’m just too tired to not be sleeping pretty solidly at night, perhaps even better (?) or maybe deeper (?) than I normally do.
I’m glad I have chosen this week to do the fast. The week prior to a week-long climbing trip because there is now way I could really do any sort of (heavy?) physical activity with the way I am currently feeling. Doing weights or having an indoor climbing session are simply out of the question. Which is, in part, why it’s taken me so long to give fasting a go. I simply could not find the time for me to do, essentially, no activity for 3 or 4 days in a row. It just doesn’t happen for me and I find it very hard to let it happen for me. A psychological remnant of my “heavier” days.
My blood glucose level and blood ketone levels are still trending in the directions I would expect, though my blood glucose is more stable than my ketone levels. Todays blood glucose reading of 68 mg/dL is slightly down on yesterdays reading of 72 but not as significant a drop as on the first day. My blood ketones on the other hand are at 3.7 mmol/L which is another large jump up from yesterdays reading of 2.5. I guess these changes (or lack of) are to be expected. The human body has a great ability to keep in homeostatic balance in quite severe conditions (like fasting), and even though everyone will react slightly differently, I’d wager most humans would react within a relatively close tolerance of each other. Both in terms of the stability of their blood glucose levels and there changes to ketone levels as they begin to burn stored fat as fuel.
The final question for me … do I keep going until tomorrow or do I break my fast tonight? I’m not sure. I feel the lethargy quite significantly and I do like to eat. I’m also conscious of the fact that I am heading away soon for a week-long climbing trip, so I want to make sure I don’t hinder my performance for the upcoming trip. I guess the question is how long do I need to “recover” from a 3+ day fast? Though really it’s still probably more about the fact that I like to eat :).
The end.
So I did some research before heading home from work tonight and I think the combination of me liking to eat, the up-coming week-long climbing trip and my desire to make sure that I do give myself enough time to “recover” has made me break my fast at 72hrs. So the night of day 3 at about 9:30pm I started eating again. The research I did, mainly on other blogs, seemed to indicate that it would be good for me to give myself a solid 2 to 3 days to recover and that I should take it slow. I decided to try to take it slower than I would have normally (so no pizza) but I did go a little harder than most blogs and websites seemed to indicate. I did have a vegetable soup and I ate a good sized portion of seedless green grapes but I did also have a nice portion of dark chocolate covered almonds as well. It’s probably not going as hard as most would think in terms of breaking fast but a lot of blogs and websites would not recommend it. Still, I wanted it so I did it and I was keen to see how I’d react.
Day 4.
So I woke up on the morning of the 4th day after break fast the previous night and I feel a lot better. The lethargy is almost gone. M bike ride into work was so much easier than the previous 2 days
that it can only be explained by the presence of food and not my bodies adaptation to fasting (it is said by some that the first 2 or 3 days are the worst on a fasting diet and that by day 4+ you feel a lot better). I do feel a little gastrointestinal … discomfort? … it’s very minor and I’m guessing, for me, that’s it more to do with simply having food in my stomach after 3 days of nothing than any true gastrointestinal upset or reaction from going to “heavy” on the food the previous night.
My blood glucose reading was back almost to normal. I measured at 87 mg/dL at work at around 10:30am. I did not have any more ketone blood strips at work today so I will not be able to measure my ketones until I get home this afternoon, after eating my lunch meal as well (so the reading will be less impactful for me but I’ll do it anyway). I do expect my ketones to have dropped though I’m keen to see if they “recover” as quickly as my blood glucose levels did. My gastrointestinal issues are rapidly subsiding.
I am definitely looking forward to eating lunch today :). I will be eating a foot long turkey sub from Subway. It’s a pretty standard lunch for me and is also my usual first meal of the day. Usually some time around 1pm or 2 pm. I expect that by this evening or Friday at the worst I will be back to “normal”. I’ve definitely gotten some things out of the experience, though how I use the experience for the future I’m not yet sure. I’ll let you know what I decide and where I go from here.
