Final answer:
During a no-carb diet, the brain uses an alternative fuel source called ketones instead of glucose. Ketones are produced by breaking down fats and can be used by the brain as an energy source. This allows the brain to function properly even without glucose.
Step-by-step explanation:
During a no-carb diet, the brain does not starve to death from lack of glucose because the body is able to use an alternative fuel source called ketones. When the body is deprived of carbohydrates, it enters a state called ketosis where it starts breaking down fats into ketones.
Ketones can be used by the brain and other organs as an energy source, allowing the brain to function properly even without glucose.
For example, muscles in the body switch from using glucose to using fatty acids as fuel when glucose is not available. The liver converts these fatty acids into ketones, which can cross the blood-brain barrier and be used by the brain as a source of energy.
The brain is capable of metabolizing ketones and using them as an efficient fuel source, ensuring its survival even in the absence of glucose.