A Fasting Day

Oops, missed a day there. Never mind. Here, as promised, is a report of my fasting day on Monday.

I started fasting after eating tea on Sunday. It was probably about 7pm by the time I'd finished my coffee (with double cream - yum!).  During the evening I drank some water, and later on some cider vinegar diluted in water. Why? Because it has been demonstrated to suppress fasting glucose levels the following morning.

The following day, Monday, I drank only water and alternative teas without milk (e.g. green tea with lemon, redbush etc).  I had a couple of twists of Himalayan pink salt - I've discovered I prefer to just eat it off my hand and chase it with water rather than dissolve it in water. The reason for taking salt is that when fasting, and on a low-carb diet, the kidneys are not forced by high insulin levels to hang on to sodium. That's why blood pressure tends to drop. This means that low-carbers and fasters, rather than moderating their salt intake as is usually recommended, need to take more.

The on Monday evening I had a bit of a wobble. There is a theory that if you are going to interrupt the fast it is better to do so with something very high in fat, since fat produces the least insulin response. I had a handful of macadamia nuts. Then a block of cheese. And then some more nuts, and a decaf coffee with cream, all at around 9.30pm. OK, so not a total fast, then, but I did wait out the rest of the time till lunch on Tuesday without consuming anything else calorific.

Here are my blood glucose and ketone readings over the length of the fast:

Monday - on waking     6.1   1.2
               - 1pm ish        5.8   1.5
               - bedtime        5.1   2.8

Tuesday - on waking     5.0   2.5
                 before lunch  5.0   2.2

As you can see, the general pattern as the fast goes on is for glucose levels to fall, and ketone levels to rise.

Glucose falls because there's no carbohydrate or protein coming in. The liver is capable of manufacturing glucose (from recycled proteins and the glycerol component of fat), and in type 2 diabetes, it does far more of that than it should.  But when there's nothing coming in, the glucose produced by the liver will be used by those body cells which can only use glucose, which is red blood cells, the cortex of the kidneys and a small part of the brain.  So there's less of it left to float around in the blood. And when glucose falls, insulin falls too - which is what I want to achieve.

A blood glucose level of 5.0, by the way, is considered normal. It's in the normal range. However, in someone who is *truly* normal - a fit, healthy active young person - it would probably be lower - especially after fasting.  So, I have a way to go on reversing my insulin resistance.

Ketones rise because, with no carbs or protein coming in, the body turns to fat for fuel. Most body cells can use fat directly, but the brain can't. So the liver makes ketones out of fat, and the brain happily uses them.  This is a process called ketosis, and is a normal part of human metabolism, there to be used when food is scarce. Except in the modern world, it is never scarce - unless we choose to fast.

Because I eat a low-carb diet, I am in ketosis all the time. My ketone levels, outside of fasting, have usually been in the high 1's/low 2's.  By contrast, someone who is having regular meals containing carbs would be unlikely to see more than 0.1

So, how did it feel?  Pretty good, actually. It's normal for me now not to have breakfast, so the only difference on Monday morning was that I had green tea with lemon rather than ordinary tea with milk. It's not a big deal to skip lunch, either. I worked in my study in the afternoon, and apart from one spell when I felt a bit 'spacey' for a short time, I was fine. I had a meeting in the evening, which probably helped keep my mind off things.  But then... oh yes.. there were the macadamia nuts and cheese. Evenings have always been my weak spot when it comes to unscheduled eating. But Tuesday morning - absolutely fine.  I worked, and then about 12.45 I made lunch, and the fast was over.

I intend to do more of this. But maybe not for a little while, as we are on holiday next week. Who wants to go on holiday and fast?  But - in honour of my new LCHF eating plan, we have booked the hotel room only. I'll probably take a couple of packets of macadmia nuts and supply of alternative tea bags, because the milk in the room is likely to be semi-skimmed (which I no longer drink, given the choice) or artificial creamer (containing sugar).  A week of seeking out suitable food choices among the cafes and restaurants of the Cotswolds. Nice!!