metabolic flexibility
The ability to switch between glucose and fat oxidation based on nutrient availability and metabolic demands.
Full Definition
Metabolic flexibility refers to the capacity of cells, tissues, and the whole organism to adapt fuel oxidation to fuel availability and metabolic demand. In healthy individuals, this involves efficiently switching between glucose utilization during fed states and fat oxidation during fasting or exercise. Loss of metabolic flexibility is a hallmark of insulin resistance and type 2 diabetes, where tissues become preferentially dependent on glucose oxidation and lose the ability to efficiently oxidize fatty acids. This metabolic inflexibility contributes to ectopic fat accumulation, further insulin resistance, and cardiometabolic dysfunction. Assessment typically involves measuring respiratory quotient changes during metabolic challenges.
Usage
Usage note: Often measured using indirect calorimetry during glucose tolerance tests or exercise protocols.
In Context
- "Impaired metabolic flexibility was evident from the patient's inability to switch to fat oxidation during overnight fasting." — Metabolic assessment report
- "Exercise training restored metabolic flexibility, improving both glucose tolerance and fat oxidation capacity." — Clinical trial results