A high-fat diet induces an increase in skeletal muscle mitochondria. Western blot analysis of mitochondrial proteins from triceps muscles of rats fed the flax seed oil/olive oil diet. Values are mean ± SE for 6–10 muscles. *, P < 0.05, high fat versus chow. C, control; F, high fat; COX1, cytochrome oxidase subunit 1; COX4, cytochrome oxidase subunit 4; ALAs, aminolevulinate synthase.