Research

Energy balance

Metabolic inflexibility in insulin-resistant skeletal muscle is characterized by a failure to suppress lipid oxidation during insulin stimulation and a failure to increase lipid oxidation during fasting.

In insulin resistance, your muscles lose the ability to switch fuels efficiently. They fail to burn more fat when fasting and fail to switch to glucose when insulin is high. This 'metabolic inflexibility' leads to lipid accumulation. Improving this flexibility is a key goal for managing insulin resistance.

GoodQualifiesHIGH confidence
The key point is that the 'higher' rate of lipid oxidation during insulin-stimulated conditions does not denote that lipid oxidation is increased in all conditions, but instead is part of an inflexibility in response to either insulin or fasting in the modulation of substrate oxidation.
D. E. Kelley et al. · Diabetes · 2000

Why this rating

Supported by limb balance methods and indirect calorimetry in multiple human studies cited.

Source

Fuel selection in human skeletal muscle in insulin resistance: a reexamination.

D. E. Kelley et al. · Diabetes · 2000

DOI 10.2337/diabetes.49.5.677

narrative_reviewCited 1,005×
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DOI resolved against Crossref · corpus check 2026-06-10

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