Ketosis is the term given to the body’s mechanism of producing ketone bodies. As discussed in the presentation ‘Ketone Bodies’, these are three compounds derived from fatty acids namely acetoacetate, beta-hydroxybutyrate and their spontaneous breakdown product acetone. Unfortunately, there is considerable confusion amongst people who should know better, namely doctors, dieticians and people in the business of nutrition, with regards to the definition of ketosis and the mechanisms evolved

The term is now used interchangeably with diets that are low in carbohydrate, and both for intermittent fasting and starvation. So, we now have a situation whereby these types of diet are otherwise known as ketogenic diets implying that the production of ketone bodies is the most important factor and is indeed desirable. Nothing in fact could be further from the truth.

Undoubtedly ketosis and thereby the generation of ketone bodies is a normal homeostatic mechanism but it is not one that should or needs to be induced in order to bring about weight loss.

As disused in the presentation entitled ‘Krebs Cycle’ and in the one entitled ‘Energy Substrate Alternatives’, the cells of the body have evolved over millions of years to utilize different energy sources, largely depending upon the availability of food. So, the cell’s primary energy source is glucose. But it can with equal ease utilize fatty acids as a secondary energy source and this of course is the aim of deliberately restricting carbohydrate, and therefore glucose, which is the concept behind the Nysteia Formula, in particular intermittent fasting.

In addition to glucose and fatty acids, the cells of the body are also able to utilize ketone bodies but it is only in unusual circumstances that these are required. All cells in the body can switch between glucose and fatty acids, with the exception of the cells of the central nervous system namely the brain and the spinal cord. The reason why they are unable to is unknown but put simply fatty acids cannot cross the cell membrane.

So certainly, in the short term these cells have a requirement for glucose. And there is a failsafe mechanism that ensures the supply of glucose never runs out and this is through gluconeogenesis which is the production of glucose from non-carbohydrate sources, in particular protein. This protein comes from both ingested and stored sources and to prevent the risk of the body using too much of its stored protein, in the form of muscle, when the ingested supply is similarly restricted, these cells are able to utilise ketone bodies after about 3 or 4 days of starvation.

For the purposes of weight loss therefore it is not important to induce ketosis, nor is it necessarily desirable because it implies that the body is undergoing starvation. This itself is not desirable mainly because it reduces your basal metabolic rate.

The one thing that is desirable however is encouraging the body to undergo lipolysis which is the breakdown of triglycerides in stored adipose tissue into fatty acids and glycerol. Fatty acids can then be transported via the blood stream to all the cells of the body and then to be utilised as effectively the primary energy source.

This process can only happen in the absence of insulin. And this therefore explains the rationale for points 1 and 3 of the Nysteia Formula namely intermittent fasting for approximately 18 hours of the day and Mediterranean type cuisine with a strict limitation on the amount of carbohydrate in the diet. If done on a daily basis this is sufficient to achieve a 1kg weight loss per week.

In reality, the three different processes involved in the supply of energy to individual cells, namely glycolysis – that is glucose production, lipolysis – the production of fatty acids - and ketosis - the production of ketone bodies, is almost certainly happening in parallel as opposed to in series. However, the extent to which each of them is happening very much depends upon the supply of carbohydrate and as previously mentioned, for the purpose of weight loss it is only really necessary to induce significant lipolysis. And this is considerably easier than inducing significant ketosis.