a-c, Blood glucose, plasma non-esterified fatty acid (NEFA), and plasma total ketone body concentrations from fed or 24 h-fasted mice (n=22, 15, 16, and 14 for fl/fl fed, CS-Mpc2−/− fed, fl/fl fasted, and CS-Mpc2−/− fasted, respectively). d, Heart weight normalized to tibia length after feeding or fasting (n=22, 15, 16, and 14 for fl/fl fed, CS-Mpc2−/− fed, fl/fl fasted, and CS-Mpc2−/− fasted, respectively). e-l, Cardiac gene expression markers of heart failure, fibrosis, or ketone and fatty acid metabolizing enzymes (n=8, 9, 7, and 6 for fl/fl fed, CS-Mpc2−/− fed, fl/fl fasted, and CS-Mpc2−/− fasted, respectively). m-o, Oxygen consumption rates (OCR) measured from permeabilized cardiac muscle fibers using pyruvate (Pyr) or palmitoyl-CoA with carnitine and malate (Palm-CoA/Carn/Mal) as substrates (n=9, 9, 9, and 7 for fl/fl fed, CS-Mpc2−/− fed, fl/fl fasted, and CS-Mpc2−/− fasted, respectively). Data are presented as mean ± s.e.m. within dot plot. Each symbol in dot plot represents an individual sample. Two-way ANOVA with Tukey’s multiple-comparisons test.