Hard low-carb and no-carb diets treat fat as the preferred fuel. That does not match how I teach the body is built to run.
Start with the red blood cell. As it matures in the marrow, it ejects its nucleus. It is the only cell in the body without a nucleus. At that point it functions as a taxi. Its job is to carry oxygen.
Oxygen rides on hemoglobin. Each hemoglobin molecule has four binding sites. Each red blood cell holds about 250 million hemoglobin molecules, which is more than a billion oxygen molecules per cell. The body moves trillions of these cells continuously to deliver oxygen, provided carbon dioxide balance is correct.
If that taxi runs out of fuel, oxygen delivery fails. Clinically that pattern is called ischemia: lack of oxygen and impaired blood flow. In this teaching, glucose is the fuel for that system.
The brain also runs on glucose. The body has many pathways aimed at making glucose and essentially one aimed at storing it. When glucose is gone, hypoglycemic coma is a known risk. That is why I do not treat glucose as optional in athlete nutrition.
When carbohydrates are removed and the body and brain are not given glucose through food, gluconeogenesis starts. Gluconeogenesis means making glucose from non-glucose sources. It is extremely energy inefficient. Related teaching on that pathway: it can cost on the order of 6 ATP to produce two glucose. The need for glucose did not disappear. The cost and the source changed.
If stored glycogen is gone, the body still has to supply glucose. It can pull from tissue, including muscle, and it can also work through fatty acids. Ketone-oriented pathways that bypass normal glycolytic routing still leave the body managing acid load. Without adequate buffering, that can mean pulling from bone or muscle to make buffers.
So in my coaching, hard low-carb / no-carb does not delete glucose demand. It forces an expensive backup system and can tax the tissue you are trying to protect. This is training and nutrition education, not a prescription for every person in every medical situation.
Watch the lesson: https://www.instagram.com/reel/DRI279Oj2v2/
— Coach Cal
Disclaimer:
This article is educational content from Coach Cal’s teaching. It is not medical advice, diagnosis, or treatment. It is not intended to cure, treat, prevent, or mitigate any disease. Individual needs vary. People with diabetes, metabolic conditions, or other medical issues should work with a qualified clinician before changing carbohydrate intake. The Wellness Lab / The Treigning Lab.
Why Low Carb / No Carb Diets Are Not Ideal
