Diabetes UK:
Ketosis is a natural state the body finds itself in when it is using fat as its main fuel. This occurs when following a very low carb, ketogenic diet, and often during intermittent fasting too.
Ketosis can be beneficial for a number of people but there are certain groups, such as people with type 1 diabetes, that need to be more careful. In these groups, very high ketone levels would lead to diabetic ketoacidosis, a dangerous situation caused by a lack of sufficient insulin.
What is nutritional ketosis?
Ketosis is a state the body goes into if it needs to break down body fat for energy. The state is marked by raised levels of ketones in the blood which can be used by the body as fuel.
Ketones which are not used for fuel are excreted out of the body via the kidneys and the urine.
Is ketosis the same as ketoacidosis?
Nutritional ketosis occurs when there is not enough carbohydrate in the diet to meet the body’s energy requirements. In this situation, the body switches over from burning sugar to burning fat as its main fuel.
Fat, whether from the diet or the body’s stores, is broken down into ketones in the liver. These ketones are an efficient energy source for many organs, particularly the brain.
Everyone has ketones in their blood at very low levels, under normal conditions. When the body enters ketosis, and so switches to burning mostly fat, levels of ketones in the blood increase.