Leucine increases muscle mitochondrial respiration and attenuates glucose intolerance in diet-induced obesity in Swiss mice

•Leucine acutely increases mitochondrial respiration through mTORC1 activation.•High-fat diet metabolic impairments are attenuated by chronic leucine treatment.•Leucine chronic supplementation prevents reduction on mitochondrial respiration.•Dietary leucine attenuates mitochondrial morphology alterations caused by obesity.