A 3-week ketogenic diet increases skeletal muscle insulin sensitivity by approximately 25% in adults with obesity, as measured by increased insulin-stimulated glucose disposal during a hyperinsulinemic-euglycemic clamp, despite no significant change in whole-body insulin sensitivity (M value), indicating a tissue-specific metabolic adaptation.

When carbohydrate intake is very low, the body produces less insulin. Lower insulin levels allow muscle cells to become more responsive to the insulin that is present, causing more sugar transporters to move to the cell surface. This lets muscle cells take up more sugar from the blood when insulin signals them to do so, improving blood sugar control in muscle tissue without changing how the whole body responds to insulin.