Introduction to the Ketogenic Diet and Ketosis
A classic ketogenic diet is a carbohydrate restricted diet consisting of a 4:1 ratio of fat to carbohydrate and protein. On a ketogenic diet, approximately 80% of calories come from the intake of fat from the diet.
On a standard western diet, glucose serves as the main source of energy for the human body. During periods of carbohydrate restriction, where glucose availability is limited, the body begins to convert fat from the diet and body stores, into ketone bodies.
The main ketone bodies produced are β-Hydroxybutyrate and Acetoacetate and Acetone. The time taken before ketones are produced varies for each individual and is dependent on starting carbohydrate stores, physical activity and the ammount of carbohydrate they consume it can take as little as 24 hours in certain conditions and as long as 2-3 weeks of carbohydrate restriction before the body begins to increase the production of ketone bodies to levels above 0.5mM, this is 10x the amount produced on a standard western diet.
When blood levels of ketone bodies rise above 0.5mM and stay between 0.5mM and 3mM, this is defined as nutritional ketosis (see figure 1). During nutritional ketosis, there is a shift away from glucose as the main source of fuel in the body and results in most of your daily energy needs being met directly by fat or indirectly by ketone bodies.
Figure 1 – The effects of different concentrations of blood ketones (mmol) on fuel flow for the brain and muscles
Ketosis has generally been portrayed as an unfavourable state associated with type 1 diabetes and starvation. However, nutritional ketosis is not to be confused with the dangerous condition ketoacidosis. Ketoacidosis is when ketone levels rise above 10mM, whereas nutritional ketosis is the result of a natural elevation of ketone concentrations between 0.5 and 3mM which has multiple therapeutic benefits. For example, the ketogenic diet has been used to treat refectory epilepsy since the early 20th century.
When a standard western diet is followed and carbohydrates are not restricted, the brain is the only organ in the body that is solely dependent on glucose as a fuel. In this state, the brain cannot use other sources of energy, such as body fat or muscle breakdown for fuel. However, when in a state of nutritional ketosis, 2/3rd of the brain’s energy can come from ketones. This means that during periods of fasting or low glucose availability, the brain’s energy demands are met by the presence of ketones, preventing any symptoms of hypoglycaemia (anxiety, irritability, intense hunger etc).
However, the ketogenic diet can be difficult to maintain, especially if one has a busy lifestyle. Even the smallest quantity of excess carbohydrate or protein in the diet, can inhibit the production of ketones and remove a person from ketosis. Furthermore, the enhanced production of ketones, through a ketogenic diet, and the usage of ketones as an energy source can take several weeks. During this period, known as keto-adaptation, individuals can experience mild hypoglycaemic symptoms, which can prove to be uncomfortable.
Supplementing with ketones can almost immediately elevate the levels of ketones in the body to a therapeutic level. Following one single dose of a ketone supplement, blood ketone levels rise to within the 0.5 – 3mM range and an individual is immediately in a state of nutritional ketosis. This induction of nutritional ketosis, through supplementation, occurs without the need for dietary carbohydrate restriction, thus bypassing the difficult period of keto-adaptation and instantly reaping the benefits of a ketogenic diet.
An elevation in blood ketones has shown to be effective in:
– Improving cognitive function
– Accelerating weight loss
– Enhancing metabolic efficiency
– The treatment of epilepsy
– The treatment of cancer
– The treatment of Alzheimer’s & Dementia
– The treatment of type 2 diabetes
And the treatment of many more diseases and conditions.
Due to the ability of Ketone supplements to initiate an immediate state of ketosis, ketone supplements can be used as an alternative method of inducing ketosis for those that do not wish to follow a ketogenic diet.
To conclude, the main benefits of exogenous ketones are the ability to initiate an immediate state of ketosis without the need for dietary restriction. Therefore, an individual can reap the therapeutic benefits of a ketogenic diet, without having to go through the difficult period of transition (keto-adaptation) and maintaining the potentially difficult to follow diet.