Short-Term Time-Restricted Feeding Alters Rhythmicity of Lipid Metabolites in Overweight Men

Time-restricted feeding may improve cellular homeostasis by dampening circadian oscillations in the metabolome of skeletal muscle. Eleven overweight males undertook two interventions during which isoenergetic meals were provided over 8-h (time-restricted) or 15-h (unrestricted) feeding. Muscle and serum samples were obtained every 4-h throughout the day and night. Untargeted transcriptomics and metabolomics revealed 4-10% of muscle transcripts and 14% of metabolites were periodic, with the relative amplitudes of oscillation in muscle metabolites signifianctly lower after time-restricted feeding. Genes periodically expressed after time-restricted feeding were mostly related to lipid and fatty acid transport. Untargeted serum metabolomics revealed 49-65% of metabolites had diurnal rhythms across both conditions: such oscilations were generally bimodal, with the periodic phase-shift likely a result of the discordant time of feeding. Core clock machinery transcripts were unaltered by either intervention, suggesting that in humans, time-restricted feeding affects periodic metabolism, but does not influence muscle core circadian clock rhythmicity.