Fig. 5. Importance of houses and nesting material for expenditure, respiratory exchange ratio, food intake, water intake, and activity level in mid-old normal-weight and DIO male mice.

Data from mice housed hide and nesting material (dark blue), with house but without nesting material (light blue), and with house and with nesting material (orange). a, c, e, and g Energy expenditure (EE,kcal/h) at housing at 22, 25, 27.5, and 30 °C, b, d, f, and h average EE (kcal/h). i–p Data from mice housed at 22 °C: i Respiratory exchange ratio (RER, VCO₂/VO₂), j Average RER(VCO₂/VO₂), k cumulative food intake (g), l average food intake (g/24 h), m Cumulative water intake (mL), n average water intake AUCs (mL/24 h), o cumulative activity (m), p average activity level (m/24 h). Data are presented as means + SEM and dark phase (1800-0600h) is indicated with grey boxes. Dots in bar graphs indicate individual mice. Statistical significance was tested by Oneway-ANOVA for repeated measurements followed by Tukey multiple comparison test. *P < 0.05, **P < 0.01. Averages were calculated over the entire experimental period (0–72 h). n = 7.