Echomri 3 in 1 qmr machine

After 18 weeks of ad-lib feeding, animals had body composition assessed via quantitative magnetic resonance (QMR; EchoMRI™ 3-in-1 QMR machine; Echo Medical Systems, Houston, TX). After QMR assessment, mice were transferred to the Comprehensive Lab Animal Monitoring System (CLAMS; Columbus Instruments Inc., Columbus, OH). Mice were single housed for accurate individual metabolic and food intake measurements and were maintained on ad-lib diets with free access to water in a 12:12 light cycle while acclimating to the new environment for 2 weeks. At 20 weeks, half of the animals on each diet were transitioned to TRF, where food access was limited to the 12-h dark period. During the next week, 24-h patterns of energy expenditure (indirect calorimetry), physical activity (beam breaks), and food intake were measured. CLAMS data were imported to ClockLab software (Actimetrics, Wilmette, IL, USA) and analyzed using the batch analysis function. Cycles 2–7 in the CLAMS cages were used for analysis. Meals were measured using the CLAMS feeding bout detection which defined a “bout” as a period where food intake was greater than 0.02 g and interbout interval was greater than 10 s. During periods of restricted feeding, food access was enforced in an automated fashion by the CLAMS. After completion of TRF (week 21), mice underwent a second QMR assessment for post-TRF body composition analysis.