a, 18F-Fluciclovine-uptake into indicated organs determined by dynamic PET scanning. n = 5 per group. b, Val oxidation (per mg tissue) in indicated tissues of mice acclimatized to 23 °C or 12 °C for one week. n = 5 per group. c, Total Val oxidation in (b). Total Val oxidation was calculated by multiplying Val oxidation per mg tissue (cpm per mg tissue) and tissue mass of the depot (mg). d, Val oxidation normalized to total protein (μg) in human brown adipocytes and white adipocytes following 2-h treatment with noradrenaline or vehicle. n = 5 (Veh), n = 6 (noradrenaline). e, Expression profile of BCAA catabolic enzymes enriched in brown and beige fat relative to white fat of humans (left) and mouse (middle, right). Data were obtained from a previous RNA-seq dataset in humans15 and a microarray dataset in mice17. The profiles were mapped onto the KEGG BCAA catabolic pathway. The number of brown and beige-enriched enzymes among total BCAA catabolic enzymes is shown. n = 3 per group. f, Proteomic profile of indicated enzymes in the BCAA oxidation pathway and mitochondrial carriers (SLC25A families) in interscapular BAT of mice at thermoneutrality (29 °C) or 5 °C for 3 weeks16. n = 4 per group. g, Transcriptional profile of indicated genes in the glucose oxidation pathway (left) and the BCAA oxidation pathway (right) in the supraclavicular BAT and abdominal WAT from the identical subject under a thermoneutral condition (27 °C) and after cold exposure at 19 °C (ref. 5). The colour scale represents Z-scored FPKM (fragments per kilobase of exon per million fragments mapped). h, mRNA expression level (FPKM) of Bcat1 and Bcat2 in differentiated brown adipocytes, beige adipocytes and white adipocytes. The transcriptome data are from a previous RNA-seq dataset15. I, Immunoblotting of BCAT1 and BCAT2 in indicated tissues of mice kept at ambient temperature. GAPDH as a loading control. Representative result from two independent experiments. Gel source data are in Supplementary Fig. 1. a–h, biologically independent samples. Data are mean ± s.e.m.; two-sided P values by unpaired Student’s t-test (b, c, f), two-way repeated measures ANOVA (a), or two-way factorial ANOVA followed by Tukey’s post hoc test (d).