Energy metabolism-metabolic rate (VO₂) and respiratory quotient (RQ)-in mice was continuously monitored throughout 12:12-h light-dark cycles before, during and after time-restricted feeding (RF). Mice fed ad libitum showed robust daily rhythms in both parameters: high during the dark phase and low during the light. The daily profile of energy metabolism in mice under daytime-only feeding was reversed at the beginning of the first fasting night. A few days after it began, RF also reversed the circadian core body temperature rhythm. Moreover, RF for 6 consecutive days shifted the phases of circadian expression patterns of clock genes in liver significantly, by 8-10 h. When mice were fed a high-fat diet (HF) ad libitum, the daily rhythm of RQ dampened day by day and disappeared on the 6^th day of RF, while VO₂ showed a robust daily rhythm. Mice fed HF only in the daytime had reversed VO₂ and RQ rhythms. Similarly, mice fed HF only in the daytime significantly phase-shifted the clock gene expressions in livers, while ad libitum feeding with HF had no significant effects on the expression phases of liver clock genes. These results suggested that VO₂ is a sensitive indicator of entrainment in mice livers. Moreover, physiologically it can be determined without any surgery or constraint. Based on these results, we hypothesize that a change in the daily VO₂ rhythm, independent of the energy source, might drive phase-shifts of circadian oscillators in peripheral tissues, at least in liver.