Ketone Bodies: What Substance Used by the Brain as an Alternative Fuel Source?
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3 min read
Approximately 20% of the body's total energy expenditure at rest is consumed by the brain, despite it only making up about 2% of total body weight. While glucose is the brain's primary fuel, ketone bodies are the substance used by the brain as an alternative fuel source when carbohydrates are scarce. The ability to utilize ketones is a vital metabolic adaptation that allows humans to survive prolonged periods of starvation or low-carbohydrate intake.