Summary of dynamic changes in shrew metabolism associated with seasonal size change, with proposed regulation of Dehnel's cycle. Depleted lipid metabolites in the blood and increased RNA expression of genes involved in fatty acid metabolism indicate rapid fat turnover in winter juveniles. FOXO signaling regulates gluconeogenesis, also upregulated in winter juveniles, providing another energy source. Both FOXO signaling and fatty acid metabolism promote changes in oxidative phosphorylation, as was found in both the transcriptomic and proteomic analyses, and have large effects on mitochondrial respiration in the liver.