Questions like this are never easy to answer. The explanations involve a lot of long, confusing words, which then themselves require definition. As I have no medical or dietary training; all I can do is try and present the results of my own reading in as clear and jargon-free way as possible. If readers’ comments can help guide my understanding, then all feedback will be gratefully received!

The below represents my own explanation of the process. I hope it helps fill in a few gaps; for what can be a tricky thing to get your head around!

We’ve already touched on the metabolic state of ‘ketosis’ in an earlier blog. But what exactly are ketones? If they promise so much, we ought at least to understand a little about them.

As we’ve seen, ketosis is a state where the body’s energy-supply comes from ‘ketone-bodies’ in the blood. This is in direct contrast to a carb-fuelled metabolism, where energy is provided by glucose. That state is termed ‘glycolysis’.

So ketone-bodies are what we burn in ketosis; but where do they come from?

In order to produce ketone-bodies, the liver’s stores of glycogen must be depleted. This is achieved through restricting your intake of dietary carbohydrate.

Glycogen is the energy-source which the body creates from glucose in the food we eat. To understand the difference between glucose and glycogen, just think of an old-fashioned coal power-station.

Coal is burnt to produce heat. That heat turns a generator, which then generates electricity. It’s the electricity which powers our homes, not the coal itself. Think of glucose as the coal (our fuel). The body converts it to glycogen, which represents the electricity (our energy). It’s the glycogen which actually powers our muscles and organs; glucose is the fuel which we process to produce that energy.

So, we restrict our glucose-intake. The body then can’t produce glycogen, which has hitherto been our primary source of energy. Our bodies then face two choices. We can either die, or we can find another source of energy to replace the glycogen. This is what ketone-bodies are; the alternate source of energy our bodies manufacture when they can’t produce glycogen.

The name for the body’s production of ketone-bodies is ‘ketogenesis’. But how does the body produce them?

Ketones are produced primarily in the mitochondria of liver cells. Mitochondria are the parts of cells which generate the energy required for those cells to work. In our power-station, mitochondria represent the generator which turns the fuel into energy.

If glucose is required to make the energy-form glycogen; what is the body’s fuel-source which enables us to produce ketone-bodies? The answer is fatty-acids.

The term ‘ketone-bodies’ may be misleading. ‘Bodies’ implies that they’re solid. In fact, they’re water-soluble. When fatty-acids are broken down for energy, they produce ketone-bodies which can then power the brain and muscles.

These ketone-bodies come in three forms:

• Acetone (the word ‘ketone’ actually derives from the old Germanic Aketon, meaning acetone)
• Acetoacetic acid
• Beta-hydroxybutyric acid (sources state this isn’t strictly a ketone, but it does the same thing, so I include it here).

It’s interesting to note that two forms of ketone-bodies are acidic. If levels of these become too high, the body enters a state of ketoacidosis. This is the poisonous ‘acidic’ state that type 1 diabetics enter when their bodies cease to produce the insulin required to process glucose from the food they’re eating.

Because the body can’t produce energy from that glucose, ketosis occurs which burns stored body-fat. When this is depleted, the body moves onto muscle-tissue in its desperate quest for energy. At this stage, ketosis turns into ketoacidosis. Un-metabolised glucose continues to build up in the blood, which then literally becomes poisonous. The results can be fatal if left untreated.

So if ketone-bodies are produced from fatty-acids, where do the fatty-acids come from?

Fatty acids can come from the food we eat, or from the body’s stored fat-reserves (body-fat). This is why you lose so much weight on a ketogenic-diet. Your body literally turns into a fat-burning machine, fuelled by the ready source of body-fat most of us have built up through excessive consumption of carbohydrate.

This makes ketosis an incredibly efficient source of energy. The body’s fat-stores are a huge fuel-tank, just waiting to be tapped. Because fatty-acids are also present in the food we eat, it’s practically impossible for that fuel-tank to run empty. This is why many athletes are turning to a ketogenic-diet: they don’t suffer the roller-coaster of energy peaks & troughs which result from burning glucose as fuel (more in that in another post).

So that’s a short explanation of where ketones come from, and how our body produces them. My brain has burned a fair few ketones, in trying to understand this process; so enough for now!

I hope you find this helpful and informative in trying to decipher the jargon.

Thanks for reading,

Adam.

When you eat carbohydrate, your body has two ways of processing it:

1. You burn it as energy
2. Your body stores it away for a ‘rainy day’, by converting it to fat.

Unless we’re incredibly active, the volume of carbs we consume is never feasibly going to be burnt off. Much of it goes straight into the store-cupboard; for that rainy day, which never comes. In this way, we get fatter and fatter.

So if we end up stock-piling all excess carbs as fat; what it is that actually does the piling? Who stocks the larder? Yes, you’ve guessed it; insulin!

Insulin is your body’s OCD housekeeper. It keeps the shelves nice & stacked with flawless efficiency! Every time you eat, it’s ready and waiting; obsessively keen to ‘tidy up’ and pack the glucose away in a never ending spring-clean.

Things might be okay if insulin just left things at that. But no.

Like all good housekeepers, insulin is fanatical about keeping busy. When it’s gainfully employed, it sends the brain a message to say “All’s fine, I’ve got plenty to do. You’re nicely full!” But when it begins to sense a lull in work, it sends the opposite message upwards: “Better eat something! You must be hungry! I need more sugar to clean-up! Eat something quick!”. You then get hunger pangs and reach for the nearest snack.

How many times have you thought to yourself: “How can I be hungry? I only had breakfast an hour ago?” Or equally: “I’m absolutely stuffed, but I suppose I could just squeeze in that one last chocolate!” That’s your brain telling you “I need more fuel!” In actual fact, all that’s happening is your sugar-levels are starting to drop.

Insulin therefore has two functions. First of all, it’s the hormone which prevents fat-burning and promotes fat-storage. And secondly? It is a satiety hormone, sending messages to your brain that you’re either full, or need more glucose!

The truly destructive thing about insulin’s secondary function, is that the message somehow gets lost in translation. The message “you’re full” actually translates to “you have enough fuel, don’t worry” The message “I’m making good progress at stockpiling all this glucose” is interpreted by your brain as “Panic stations! You’re running out of energy!”.

There’s a distinct language-barrier between the two; one that ends up in mixed signals, and leaves you craving sugar, despite the fact you’ve just had lunch!

So how do we get around this confusion in meaning? Is there a way to stop your brain thinking it’s running out of energy as soon as your blood-sugars start to drop?

The answer is ketones and saturated fat.

Your brain can burn either of two fuels: glucose or ketone-bodies (it can even burn both!). Unlike glucose, ketones are a constant source of energy for the brain. They’re produced by the body, so are not dependent on your food-sources to keep the brain happily fueled. Ketones are only produced when glucose is unavailable. Therefore cut your carbs.

Because fat is far slower to metabolise than glucose, it slows down digestion when it enters the intestinal-tract. When you’re busy digesting, your brain knows that you’re full and your appetite is decreased.

This message is fundamentally different from the ‘drama-queen’ signals fired off by your OCD insulin-housekeeper! It’s a reliable message, where both parties speak the same language. To take advantage of this message, eat more fat.

A fat-metabolism prompts you to eat when you’re hungry, then stop when you’re full.

Glucose drives you to eat to when your sugar-levels drop; it has nothing to do with how much you’ve eaten or whether you need food.

In understanding this, lies to key to harnessing your metabolism and regaining control of your relationship with food.

The ketogenic-diet allows you to lose weight with no hunger pangs. There’s no desire to snack, nor do you suffer the roller-coaster ‘highs and lows’ associated with drops & spikes in blood-sugar.

For me, it’s time my OCD housekeeper took a holiday. And I’m going to do all I can to make sure it’s a permanent one.

And no; I don’t need a postcard!

Thank you for reading,

Adam.

Fibre is a wonderful thing! Not only does it ensure that the food we eat ‘keeps moving’ through the digestive-system; it can actually help lower cholesterol and aids the prevention of a whole host of nasties… (NHS states heart disease, diabetes, some cancers &tc).

Whilst I can’t comment on the ‘preventative’ health-qualities of fibre; I can tell you a little bit about it, and why it’s so important to the ketogenic-dieter or diabetic.

People are often surprised to learn that fibre is actually a form of carbohydrate (alarms bells ring for all low-carb readers everywhere!!!). Having said this; it comprises the parts of plants which we cannot digest and is therefore not absorbed by the body. As such; it’s not a nutrient and contains no calories or vitamins.

Examples of indigestible plant-fibres include cellulose (the plant’s cell-walls), lignin (derived from the Latin word for wood & the thing which makes vegetables crunchy); and suberin (a waxy, rubbery material which is water-resistant, therefore acting as a barrier to moisture-loss in roots, bark &tc). Such fibres are not absorbed in the small intestine and pass straight through to the large intestine intact.

Because fibre is ‘rough’ and combines with other foodstuffs to ‘shift’ them through the digestive-tracts; it contributes to feelings of ‘fullness’/ satiety. This is a major advantage to both dieters and weight-stable people alike! The fuller you feel, the less you’ll eat!

Fibre comes in two forms:

• Soluble fibre
• Insoluble fibre

So what’s the difference?

Soluble fibre does as the name suggests: it attracts water and dissolves into a form of ‘gel’ in the gut. This gel helps to slow-down the digestion of other foods, including (yes!) carbohydrate and sugar. This is particularly important for diabetics. Why?  The slower the rate of carbohydrate-absorption in your system, the more stable your blood-sugars, and the lower the risk of glucose-spikes in the blood-stream.

Stable blood-sugars = better insulin management = improved health!

Examples of soluble fibres include fruits, legumes, oats (all forms of fruit & vegetables to varying extents).

Insoluble fibre is equally aptly named. It’s made of the more structural parts of plant (the lignins &tc). As a result, it also attracts water, but instead of forming a gel; it ‘puffs up’ & adds bulk/softness to other less fibrous foods. In-so-doing, it regulates the passage of foodstuffs through the intestines, thereby promoting digestive health in general.

Examples of insoluble fibres include bran, beans, green leafy vegetables, nuts & seeds.

So we know what it is and what it does. But why is fibre of special importance to a low-carb diet?

Firstly, low carb diets often consume a higher proportion of meat & dairy products than other regimes. These require good levels of fibre to secure their transit through the digestive-system

Secondly (and of supreme interest!) – because dietary-fibre is a carbohydrate which comprises the indigestible parts of edible plants; fibre should be subtracted from the total carbohydrate-content of foods, because we cannot digest it!

Yes – we minus fibre from carbohydrate whenever we calculate the carb-value of what we’re eating. This reduced figure is termed the ‘Net Carbs’ (i.e. the true nutrient-value of the carbohydrate we’re consuming; not the parts which pass straight through intact).

For many foods, this will render what seems like a high carb-value into something that’s both acceptable, and can be eaten freely on a ketogenic-diet.

Example: Carbohydrate 10g minus fibre 8g = net carbs 2g.

Sugar-alcohols should also be subtracted, but these are often hard to distinguish on UK food packaging, so are omitted from this post.

Armed with this quick and easy ‘carb-counting-tool’; shopping, cooking & ‘living’ a low-carb diet all become instantly easier and more accessible!

I hope this helps and thanks for reading,

Adam.