(Ay/a; C57BL/6J;#002468) and UCP1−/−C57BL/6J;#003124) mice were obtained from Jackson Labs and bred in-house. All
animals were housed at constant temperature (19 −23°C) in 12 h
light/dark cycles with free access to water and standard chow (Harlan Teklad
Global Diet 2020X). For high fat feeding, C57BL/6J mice were provided with
Harlan Teklad diet#TD06415 (45% calories from fat); for calorie restriction
(
were measured for singly housed mice; then mice were 25% calorie restricted
using a 60% mix of AIN93M:40% CR (Bioserv cat#F05314) in control diet (AIN93M,
Bioserv cat#F05312), pair-fed daily at 5 pm, for 5 weeks.