Difference in Housing Temperature-Induced Energy Expenditure Elicits Sex-Specific Diet-Induced Metabolic Adaptations in Mice.

OBJECTIVE: The aim of this study was to test whether increased energy expenditure (EE), independent of physical activity, reduces acute diet-induced weight gain through tighter coupling of energy intake to energy demand and enhanced metabolic adaptations.
METHODS: Indirect calorimetry and quantitative magnetic resonance imaging were used to assess energy metabolism and body composition during 7-day high-fat/high-sucrose (HFHS) feeding in male and female mice housed at divergent temperatures (20°C vs. 30°C).
RESULTS: As previously observed, 30°C housing resulted in lower total EE and energy intake compared with 20°C mice regardless of sex. Interestingly, housing temperature did not impact HFHS-induced weight gain in females, whereas 30°C male mice gained more weight than 20°C males. Energy intake coupling to EE during HFHS feeding was greater in 20°C versus 30°C housing, with females greater at both temperatures. Fat mass gain was greater in 30°C mice compared with 20°C mice, whereas females gained less fat mass than males. Strikingly, female 20°C mice gained considerably more fat-free mass than 30°C mice. Reduced fat mass gain was associated with greater metabolic flexibility to HFHS, whereas fat-free mass gain was associated with diet-induced adaptive thermogenesis.
CONCLUSIONS: These data reveal that EE and sex interact to impact energy homeostasis and metabolic adaptation to acute HFHS feeding, altering weight gain and body composition change.