Glucose, from carbohydrates, are the primary fuel for the body’s cells and organs when eating a standard western diet.
Cells obtain energy by taking up glucose from the blood, where a metabolic reaction takes place to release energy. Our bodies store excess glucose in the form of glycogen, so that we have energy for later use.
Glycogen (made up of long chains of glucose molecules) is mainly found in the liver and skeletal muscle. Liver glycogen stores maintain normal levels of glucose in the blood. Whereas stored muscle glycogen mainly fuel muscle activity.
When eating a Low carb High Fat diet fats and proteins can provide most of your body’s energy requirements. Most body cells are able to use fatty acids for energy. Brain cells and developing red blood cells are the exception, as they depend on glucose. A supply of glucose in the blood is therefore essential, however brain cells can adapt to use ketones from fat breakdown for energy.
When restricting carbohydrate intake the liver does not break down fat completely. Instead, the liver makes ketone bodies that can be used by most cells for energy.
Nutritional ketosis occurs on a LCHF diet when ketones are produced more quickly than the body needs and their levels increase in the blood. As glycogen stores deplete the body switches to burn body fat, increasing fatty acids availability as a fuel source. Many of these fatty acids cannot pass the blood brain barrier, so the brain switches to using ketone bodies, produced by the liver, as fuel.
This is the nutritional ketosis process, the normal and extremely efficient physiological response to carbohydrate restriction.
Dr. Benjamin Bikman, Ph.D. in Bioenergetics and Professor of pathophysiology and a Biomedical Scientist at Brigham Young University in Utah.
Dr. Bikman’s special professional interest in obesity and diabetes and the pathogenicity of insulin and insulin resistance.
He has long been an advocate of the ketogenic diet approach for reversing insulin resistance and on exploring the intimate associations between the metabolic and immune systems.