What is Ketosis
Ketosis is a state of elevated levels of ketone bodies within the body. Ketones are a preferential fuel source for the brain and muscles.
What is the advantage
Within our liver and muscles we can store a maximum of about 1800 calories of glycogen. For HARD exercise this means we have about 1 hour 50mins worth of energy. Conversely an average athlete has about 65,000 calories of stored fat.
Ketones also burn 'clean' meaning less destructive bi-products compared to sugar which our bodies would need to process or clear.
By using body fat ketosis is a great way to 'lean up' whilst still maintaining energy levels as well as reducing blood glucose and insulin.
How do we measure it.
There are two methods of measuring ketones - urine or blood. The difference is in the type of ketones measure. Urine analysis measures levels of Acetoacetate. Logically what appears in urine is what the body is trying to get rid of rather than what is used. Blood analysis measures beta-hydroxybutyrate which are used by the muscles and brain for energy so is a better indicator of what is available and being utilised.
Blood analysis is performed using a simple meter (most of which can also measure blood glucose) available from chemists for under $50.
What is Nutritional Ketosis
Nutritional Ketosis is the 'sweet spot' for ketosis where blood ketones are in the range of 0.2 2.0 mmol/l
Can it be harmful
Yes. Above 5mmol/l starts to move into what's called Ketoacidosis effecting the acidity of blood. It is also strongly not recommended for type I diabetics.
How do I do it.
In simple terms a high fat / low carb diet is used to enable ketosis however the risk of too much fat as a ratio can push the body into ketoacidosis. Similarly too much protein can lower the ketone level through a mechanism called gluconeogenesis. It is commonly found that a diet ratio of 80% fat, 15% protein and 5% carbohydrate is optimal for nutritional ketosis.
Intermittent fasting has also been shown to increase blood ketones.
Isnt that Atkins ?
No. Atkins is high protein, high fat which as mentioned reduces blood ketones through conversion of protein to glucose.