Indirect calorimetry analysis of Ctrp5-null mice fed a high-fat diet. A–D: oxygen consumption (V̇o2), CO2 production (V̇co2), respiratory exchange ratio (RER), and energy expenditure (EE) for male WT and KO mice at 22 wk of age. E: total physical activity levels for WT and KO mice during the dark and light phases of the photocycle. F: real-time food intake measurements for WT and KO mice during the dark and light phases of the photocycle. G: cumulative food intake (over a 12-h period) for WT and KO mice in the dark and light phases of the photocycle. (WT, n = 6; KO, n = 8).