146.17 average

wow! I wasn’t expecting quite such a large drop in weight this morning! As I mentioned in yesterday’s post, however, that is not what I would consider my actual weight. I go by the average so I’m really more like 146.17lbs. Because of yesterday’s fast, I’ll be low on water due to glycogen depletion. Glycogen is the form of sugar the body stores in its muscles. The foods (particularly carbohydrates) you eat get converted into glycogen, are bundled up with water and stored in the muscles for them to use as energy for movement. Water is heavy so if you use up the glycogen, the water goes, too. Getting fitter is partly about increasing the muscles’ ability to store this vital energy and to utilise it effectively.

When you exercise, you are using either the sugars in your muscle or the fat reserves which are converted into usable sugary by your liver (more on that later). It’s almost always a combination of the two that’s driving the engine but high intensity exercise increases sugar consumption from the muscle, depleting the glycogen. Recent studies showed that doing high intensity interval training (in which you go at the peak of your capability for a brief period of time – e.g. 30 seconds or 2 minutes – followed by either light exercise or complete rest) led to diabetic subjects showing improved insulin levels. When you clear out the glycogen in your muscles, the excess sugar in your bloodstream can be hoovered up by these empty muscles.

Fasting does a similar trick and there seems to be something very important about removing glycogen in your muscles for a refreshing later that is superior to just keeping the muscles continually topped up through regular meals or through no exercise.

I’m not saying fasting is equivalent to or can replace exercise. Fasting won’t make you fitter but it does seem to mimic some of the chemical processes that are part responsible for the healthy side effects of exercise. Fasting, like high intensity exercise, clears out the muscle of its glycogen and allows excess sugars to flood in its place.

I do both, though. I cycle 5.5 miles to work and 6.5 miles back (it’s a slightly different route home) whether I’m fasting or not. Some weekends TSC and I go touring on our loaded up bikes and cycle ten times that distance, camp a night and then cycle on again the next day. How I’m going to incorporate that level of glycogen depletion while fasting is something I am going to have to play around with and be flexible on, I think.

Critics of fasting point out (quite rightly) that the brain is not a muscle and does not have glycogen stores to draw on when you’re not taking in any carbohydrates. (They criticise low or no carb diets with this same fact). The brain requires glucose to work. Glucose is what all carbohydrates are converted into (be they simple carbohydrates in a cake or complex carbohydrates in porridge. the difference is only how much ‘lab work’ the body has to do with it to convert it into usable glucose). But the body is perfectly capable of producing its own glucose, otherwise we’d all die if we skipped breakfast. People can survive weeks on no food as long as they have enough fat reserves.

The liver is capable of converting fat into sugar. Each molecule of phospholipid fat is made up of a glycerol ‘head’ with three fatty acid chain ‘tails’ (made up of carbon atoms, connected to hydrogen atoms. Where each carbon has two hydrogen atoms each, it’s considered ‘saturated’. Where carbon atoms are missing a hydrogen and have to connect to another carbon atom, it is ‘unsaturated – bit of useless info for you there). Glycerol on its own is a sweet substance (technically an alcohol) that is used for making cough medicines as it tastes sweet and is quite viscous.

The liver can happily pick apart the fats, remove the glycerol part and put it into the bloodstream. This is why on fast days you can be less hungry than on non-fast days. Hunger is complicated and is affected by a number of things including stretch receptors in the stomach, hormones such as insulin and ghrelin  and a whole host of psychological goings on, too. Slumping blood sugar levels can make you hungry. This is typically caused by over consuming sugar, insulin is released to sweep up the excess sugar but sometimes it goes overboard and sweeps away too much, leading to low sugar levels in the blood, which sets the brain off to wail for more sugar (and you get that ‘can’t concentrate’ feeling). This is why a lot of diets fail so badly. Your body senses there is a below acceptable level of sugar in the blood. Your brain really needs it and starts to scream for some sugar. Your brain is screaming for sugar and guess who’s in charge of controlling the hand that buys the chocolate bar, hmm? This is why dieting breakdowns are not necessarily your fault. Willpower is all very well but it’s naive to think you have complete conscious control over your brain.

But, if you can leave it for a bit or have no access to food, eventually your liver kicks into gear and starts fatty acid chain crunching and puts sugar into your bloodstream from the fat reserves you have (I did read about a theory that said one reason why bum fat is so much harder to shift than belly fat is because it’s so much less accessible to the liver. I’m not sure how true that is and can’t find anything on it, either. I can vouch that I personally lose belly fat before it moves from my bottom but I’m a pear shape and I think genetics plays the biggest part in where your fat is stored. It  might just have been a theory and nothing was proven). So your liver can keep the bloodstream supplied with a steady supply of sugar. Not having the ups and downs caused by insulin prevents one of the mechanisms of hunger.

For some reason, eating protein also suppresses hunger.  Again I’m hazy on the details but I think it affects another hormone (ghrelin) to make you feel sated. This is why carbohydrate breakfasts stay with you less long than do protein based breakfasts such as an egg or sausages. Don’t believe me?  Start a few days with some protein only (doesn’t have to be fatty. Lean protein would be better) and see how you feel by lunchtime.

Cycle touring around Germany TSC and I started our days with either porridge or German sausages for breakfast. There was no contest when it came to midday munchies. We could go through to the afternoon before eating when we’d started our day with Würstchen. For the TSC not to feel hungry within a few hours of eating is unheard of. He’s one of those ‘needs to eat every few hours’ kinda guys.

It’s a good job the body is not a slave to carbohydrates for its brain fuel thanks to the liver. Incidentally, in studies involving rats, the fasting little rodents had healthier liver function than did the control group of non-fasting rats. The body is an amazing thing. Converting this to that, that to this. We’re quite the chemical lab. Good job too, or all the Atkins lot would be dead or zombies. None has suffered brain damage as a result of not eating carbohydrates as far as I know. Carbohydrates are probably the only macronutrient (the other macronutrients are protein and fat) that we can actually live without. I’m not saying we should. I’m not advocating carbless diets but if you refused to eat protein or fat, you would die.

Anyway, that’s enough chemistry lesson. I’m off for some brekkers.  Muesli with some banana. yum yum. I won’t want protein for breakfast or I might end up skipping lunch and this is a Food Day.

Eats: 1 milk-tea | 1 muesli w/ semi skimmed milk | 1 banana | small portion of rice | 2 pecan biscuits | 1 toast w/salmon and tomato | 2 slices homemade bread | spaghetti bolognaise | chocolate brownie w/custard

Exercise: short cycle ride to shops