What is Ketosis?

When following a low carbohydrate diet, the body enters a natural state called ketosis. This is when the body breaks down fat for energy instead of glucose.

Nutritional Ketosis is not recommended for diabetics due to the lack of an evidence base. 

How do you enter ketosis?

It may take 2-3 weeks of low carbohydrate consumption (typically 50g of carbohydrate per day or less) before your body enters ketosis.

But doesn’t the body need carbohydrates to survive?

Yes it does. But, there are a small amount of carbohydrates found in most foods.

What about glucose?

The body also requires glucose, which is why during ketosis the body converts protein into the glucose it needs in a metabolic pathway called gluconeogenesis (GNG). This is why, if you are a type 1 diabetic and restrict your carbohydrate consumption, you will see a slight rise in blood glucose levels 1-2 hours after consuming a meal – this is when the body processes the protein into glucose.

Ketosis and exercise 

Being in a state of ketosis is, in my opinion, fantastic for some people who are into endurance activities. Ever wondered, when people talk about hitting ‘the wall’ during a marathon, what ‘the wall’ is? It happens when the body has depleted its maximum stores of carbohydrates – which is approximately 2,000 calories in the human body. ‘The wall’ doesn’t really exist if you’re in nutritional ketosis – because the fat fuel stores within the body typically contains over 40,000 caloriesWhich is why I was able to run a 32km mountain race with a 1300 metre elevation consuming nothing but water for the entirety of the five and a half hours it took me to complete the route…and yes, I’m a type 1 diabetic.



How do you know if you’re in ketosis?

You can buy ‘Ketostix’ from a Pharmacy or from Amazon (under £6 for 50 strips). You pee on them and they give you an indication of what level of Ketosis you are in- if at all. They’re not the most accurate way of working out your ketone production level (at all), but they’re far cheaper than buying ketone blood strips (which retail at about £26 for 10 strips! However, if you’re a type 1 diabetic you should be able to get ketone strips on prescription).

But aren’t ketones bad

Not necessarily.

Here are a few excerpts about Ketones from Eric Westman MD and Jimmy Moore’s fantastic book, Keto Clarity: 

‘It’s important to remember that when your blood sugar level is in the normal range, the presence of high levels of ketone in the urine, blood or breath is not at all harmful, no matter how much weeping or gnashing of teeth you may hear from your health gurus. Diabetic ketoacidosis…tends to occur mostly in type 1 diabetics…and only when blood sugar levels are in excess of 240 mg/l (14.4mmol/L) and blood ketone readings well in excess of 10 millimolar per litre.’ 

‘Ketones are merely a by-product of burning fat for fuel. In other words, burning fat generates ketones at the same time. When you are keto-adapted, you generate energy from both your body fat and dietary fat.’

‘Ketones are actually the preferred fuel source for the muscles, heart, liver and brain. These vital organs do not handle carbohydrates very well; in fact, they become damaged when we consume too many carbs.’

Why I want to be in ketosis

Being in ketosis is similar to eating low carb in that:

  1. I can go to sleep each night knowing that I will wake up with the same blood sugar level in the morning (always between 4 and 5 mmol/Ls).
  2. My insulin requirements are down to an absolute minimum – no large doses for basal, no large doses for meals. If I forget to inject for a meal – or if I’m eating out and I forget my insulin, or the cartridge runs out – there is no panic, because eating low carb means that any rise in blood sugar is minimal.
  3. I don’t have to worry about going high or dropping low during a lecture or practical in the laboratory.

But what ketosis does is take my health up a notch, to what I would describe as optimum health. And this has everything to do with exercise. Whilst in ketosis, I am able to have the freedom to run as I did pre- my type 1 diagnosis. I am able to run mid-long distance without the fear of hypo-ing, and without the need for carbohydrates or glucose to sustain me. An example of this is when I ran a 32km alpine mountain race (1300 metre elevation) with nothing but water. I am able to take part in gym classes – high or low intensity, short or long durations – swim, or play a team sport – and my blood sugar will remain stable. For most, just eating low carb is more than sufficient enough to achieve fantastic blood glucose levels – and indeed, it does for me. I just love ketosis for removing the limitations that diabetes put on me whilst living an active life.

Other great exercpts from Keto Clarity

  • ‘By far, the greatest criticism of ketogenic diets is that ketosis is unhealthy, dangerous, and can even cause death. But where are the bodies? If it’s so dangerous, why aren’t the casaulties piling up? More to the point, why does it keep saving so many lives?’ John Kiefer
  • ‘Using nutritional ketosis to prevent and treat diseases other than epilepsy and obesisty is a relatively new concept. So there are currently no large clinical trials in existence. Even most biochemistry textbooks hardly mention ketosis except in reference to starvation and diabetic ketoacidosis.’ Dr Zeeshan Arain
  • ‘Our studies suggest that the major protective effect of ketosis is a significant reduction in glucose metabolism. This is the opposite of diabetes.’ Dr. Charles Mobbs
  • ‘There is no such thing as an essential carbohydrate’ (Nora Gedguadas)
  • ‘There is not enough data to prove enough data to prove that ketosis is dangerous.’ – Stephanie Person


Nutritional Ketosis (Ketosis) is a state of health in which your body is burning fat for fuel instead of gluocose.

Ketone bodies (Ketones) are molecules that are produced by the liver from fatty acids in carbohydrate restricted diets.

Diabetic Ketoacidosis (DKA) occurs when the body suffers from a severe lack of insulin, resulting in high blood sugar levels whilst disabling the bodies’ ability to access glucose in the bloodstream to use for energy. As a result, the body starts to break down other body tissue as an alternative energy source.