Fig. 1: Elevated NADH drives the daytime dip in body temperature during time-restricted calorie restriction.

a, Model for the TRF-CR diet using an automated feeder system in 4–6-month-old male C57BL/6J mice. Control mice received a 300 mg pellet of regular chow every 1.2 h throughout the dark period (TRF-Reg), whereas TRF-CR mice received a 300 mg pellet of a carbohydrate-depleted, nutrient-controlled chow every 2 h throughout the dark period, resulting in a 40% reduction in calories. b, Relative concentration of NADH and NAD⁺ by HPLC in liver of TRF-Reg (n = 12) and TRF-CR (n = 11) mice during the daytime (ZT4). c, log₂(fold change) in daytime serum acyl-carnitine levels during TRF-CR compared with TRF-Reg mice (n = 3). d, Body temperature rhythms monitored non-invasively using subcutaneous probes in TRF-Reg (n = 12) and TRF-CR (n = 9) mice over 24 h (double plotted for clarity). e, Model depicting NADH-consuming reaction of LbNOX. Representative tissue-specific expression profile of cytonuclear LbNOX in null- and LbNOX-transduced mice relative to LbNOX-transduced liver. f, Relative concentration of NADH and NAD⁺ in liver of null- and LbNOX-transduced TRF-Reg (n = 6) or TRF-CR (n = 5 for NADH, n = 6 for NAD⁺) mice during the daytime. g, log₂(fold change) in daytime serum acyl-carnitine levels in TRF-CR mice transduced with cytonuclear LbNOX compared with TRF-CR mice transduced with null virus (n = 3). h, Body temperature rhythms in LbNOX-expressing TRF-Reg (n = 12) or TRF-CR (n = 9) mice over 24 h (double plotted for clarity). Data are presented as mean ± s.e.m. Statistics were performed with unpaired, two-tailed Student’s t test unless otherwise noted in the figure. *P < 0.05, ***P < 0.001. ANOVA, analysis of variance; Cereb, cerebellum; DC, dicarboxylate; Gastroc, gastrocnemius muscle; gWAT, gonadal white adipose tissue; Hypoth, hypothalamus; i, isomer; iWAT, inguinal white adipose tissue; OH, hydroxy; Quad, quadriceps muscle.