I've been doing intermittent fasting for over a year, not out of any grand plan but it's just a natural fit for me. I was doing it before I knew it was a 'thing' and had a name. I've also done 36- or 42-hour "fasts", where I don't eat for a full day. Though they weren't true fasts, I always allowed myself a few hundred calories of fat/protein.

Earlier this month I got interested in trying an extended fast, so I read Dr Fung's book A Complete Guide to Fasting, and used that as my guide. My original plan was for a 3- or 4-day fast, but if I felt good, to keep it going as long as I could.

I started on Wednesday July 19th, with my last food logged at 17:40. The first day wasn't bad, I had a few instances of feeling 'hungry' but that was more due to routine. As in, 'this is the time I normally eat so why aren't I eating now?' kind of thing.

According to Fung's book, day 2 is usually the worst for hunger, but I didn't find it so. I suspect the people who really struggle on day 2 are not normally LCHF / keto, so that's when their stored glucose completely runs out and they're struggling with the switchover to burning fat. Anyhow, the second day wasn't much of a challenge for me, in terms of hunger.

I did experience very vivid dreams which led to slightly disrupted sleep - I could usualy fall asleep ok but had trouble staying asleep, and tended to wake up too early and be unable to get back to sleep.

I will also note, I maintained my normal excercise routine during the fast - one to two hours per day, every day, of cardio. Either walking or cycling, and usually a bit of both.

During the fast, I was still having coffee, with a splash of heavy cream, and I continued to use my zero-calorie sweetener despite Fung's recommendation against it. I also continued flavouring my water with Mio, against recommendations. I can't drink plain water, and felt that it was more important to be hydrated than to spoil the 'spirit of cleansing' or whatever. In my defence I never use as much of the flavour drops as they say - I just use enough to mask the taste of the dreck that comes out of my home's 100-year old pipes.

I also made up a big batch of bone broth, which I planned to use to supplement sodium and other micronutrients. I found that I couldn't force myself to drink that either. I've never liked soup or broth. On the third day, I ended up just making the bone broth into a big batch of low-carb BBQ sauce and stuffing it in the fridge. Though I did have a couple spoonfulls of the sauce - the spicey savoury kick was refreshing.

The next couple of days continued fairly uneventful - I had coffee, tea, and some Zevia soda when my stomach was gurgling. Through it all I never really felt seriously hungry, which was a nice surprise.

On the Monday night I did get some hunger pangs, but I was watching a bunch of cooking shows and realized it was probably just a reaction to the food on the TV. I drank some water and the feeling passed.

One of the things I had said all along was as long as I felt good I would continue fasting, and if I stopped feeling good I would stop the fast. Through the first 6 days, I felt good. No real hunger, no weakness, no lack of energy. In fact I was feeling so good the morning of day 6, that I was hoping to extend the fast untill Sunday July 30th.

On the afternoon of the 6th day (Tuesday) I had some work-stuff come up that added some stress. The stress seemed disproportionate though, like the work stuff wasn't that big a deal but I was over-stressed about it. That evening I got a case of the munchies, I kept wanting to eat. I wasn't hungry per-se but I had persistent food-thoughts, of meat, spice, salt. I drank water and it passed, but in retrospect that might have been a first sign.

That night I didn't sleep well, which I attributed to the stress. By the morning of Wednesday July 26th, day 7, I was tired and still stressed. I did my scheduled morning workout, an 8+ km walk, but towards the end I felt very tired and felt my energy waning. I chalked up the extra tiredness to the lack of sleep, but by mid-day I had determined that if I wasn't feeling better the next day, I would break my fast.

Wednesday afternoon after I had got the work stuff finally taken care of, I had a hot soak in a bubble-bath to try and relieve the stress. I followed that up with a cool shower. And that's when my body told me, in no uncertain terms, it was time to break the fast.

At the worst possible moment, I had such a dizzy spell I nearlly blacked out then and there in the shower. Tunnel vision, things going dark, flashes of light. I ended up laying a towel ontop of my bed and then just collapsing on that for about an hour, until the dizziness passed. Then I got up and broke my fast at 16:40 - one hour short of a full 7 days.

As Dr Fung suggests, I broke it with a small meal first; I used some olives and a bit of prosciuttino. Then an hour or so later I had a larger meal, some bacon-wrapped scallops. I had some pistachios a while later, and then felt I was full.

Today and tomorrow I will have slightly larger meals than normal, though I will stay on my keto and IF plans.

And I will add, I am feeling back to normal this morning - feeling good again, energetic, no tiredness or weakness.

I've been trying to determine what ultimately caused me to break the fast. Was it the added stress? Lack of sleep? Or was the added stress due to the fast? Was the lack of sleep due to stress, or due to the fast? Was it a combination of factors? Likely.

I may have been pushing myself too hard all week, by maintaining the same excercise routine. According to the Apple Health app, I was burning an average of about 3000 calories per day (basal + activity). According to my food diary, I was taking in say about 100 calories per day. According to calculations, I probably only had access to about 2800 calories per day from my fat reserves (see here: http://blog.2keto.com/why-fasting-is-easier-for-some-people/ ). So I was definitely pushing myself a little too close to the wire, if not past it.

Despite the abrupt and unplanned ending, I have to say overall I am pleased with the outcome.

I will definitely try this again in another month or so. I didn't think to do before- and after- weigh-ins, because weight-loss was not my primary goal for the extended fast. I typically weigh myself Sunday mornings, but my fast was Wednesday evening to Wednesday evening. Next time I'll try a Sunday to Sunday fast so I can gauge its effect on weight.

My interests this time around were other beneifts, namely helping fight insulin resistance, higher levels of human growth hormone, and increased autophagy. And the biggest one, was 'Can I actualy do this?' And the answer to that, is yes, I could!

Now, time to go make something to eat!