Effects of 12 Months of Caloric Restriction on Muscle Mitochondrial Function in Healthy Individuals

Context: The effects of caloric restriction (CR) on in vivo muscle mitochondrial function in humans are controversial. Objective: To evaluate muscle mitochondrial function and associated transcriptional profiles in non-obese humans following 12 months of CR. Design: Individuals from an ancillary study of the CALERIE 2 randomized, controlled trial were assessed at Baseline and 12 months after a 25% CR or ad libitum (Control) diet. Setting: The study was performed at Pennington Biomedical Research Center in Baton Rouge, Louisiana, USA. Participants: 51 (34 females, 25-50 years of age) healthy non-obese individuals randomized to one of two groups (CR or Control). Intervention: 12 months of a 25% CR or ad libitum (Control) diet. Main Outcome(s): In vivo mitochondrial function (ATPmax, P/O) by 31P-MRS and optical spectroscopy and body composition by DXA. In a subset of individuals, a muscle biopsy was performed for transcriptional profiling via qRT-PCR and microarrays. Results: Weight, BMI, fat and fat-free ma...