Figure 8. Sex differences in CR-induced weight loss and fat loss are absent when CR is initiated in aged mice.

Male and female C57BL6/NCrl mice were single housed and fed AL or a CR diet (70% of daily AL intake) from 78 to 84 weeks of age. (A–F) Each week mice were weighed (A,B) and body composition was determined by TD-NMR (C–F). Body mass, fat mass and lean mass are shown as absolute masses (A,C,E) or fold-change relative to baseline (B,D,F). (G) Masses of gWAT, iWAT, mWAT, pWAT, pcWAT, and BAT were recorded at necropsy and are shown as % body mass. Data in (A–F) are shown as mean ± SEM. Data in (G) are shown as violin plots overlaid with individual data points. For each group and timepoint, the following numbers of mice were used: (A,B): male AL, n=9 (Wk 0, Wk 2, Wk3, Wk 4), 8 (Wk 1), or 6 (Wk 5, Wk 6); female AL, n=13 (Wk 0, Wk 2), 12 (Wk 4, Wk 5), 11 (Wk 6), 9 (Wk 1), or 8 (Wk 3); male CR, n=10 (Wk 0, Wk 2–4), 9 (Wk 1), 7 (Wk 5), or 6 (Wk 6); female CR, n=14 (Wk 0, Wk 4, Wk 5), 13 (Wk 2, Wk 6), 10 (Wk 3), or 9 (Wk 1). (C–F): male AL, n=9 (Wk 0, Wk 2), 8 (Wk 3, Wk 4, Wk 6), or 7 (Wk 1, Wk 5); female AL, n=13 (Wk 0, Wk 2), 9 (Wk 4, Wk 6), 8 (Wk 5), 6 (Wk 1), or 5 (Wk 3); male CR, n=10 (Wk 0, Wk 2), 9 (Wk3-6), or 8 (Wk 1); female CR, n=14 (Wk 1, Wk 2), 11 (Wk 4–6), 7 (Wk 3), or 6 (Wk 1). (G): male AL, n=9; female AL, n=12 (iWAT, mWAT) or 11 (gWAT, pWAT); male CR, n=10 (iWAT, pWAT), or 9 (gWAT, mWAT); female CR, n=14 (mWAT, pWAT), 13 (iWAT), or 12 (gWAT). For (A–F), significant effects of diet, sex and/or time, and interactions thereof, were determined by three-way ANOVA or a mixed-effects model. For (G), significant effects of sex, diet, and sex-diet interaction were assessed using two-way ANOVA with Tukey’s multiple comparisons test. Overall p values for each variable, and their interactions, are shown beneath each graph. For (G), significant differences between comparable groups are indicated by ** (p<0.01) or *** (p<0.001). Source data are provided as a Source Data file. See also Figure 8—figure supplement 1.

Figure 8—figure supplement 1. CR and sex effects on the masses of adipose and non-adipose tissues in aged mice.

Male and female mice were fed AL or CR diets from 78 to 84 weeks of age, as described for Figure 7. After six weeks of CR (84 weeks of age) tissues were sampled and weighed. (A–C) Violin plots, overlaid with individual data points, showing the absolute mass (A,B) or % body mass (C) of each tissue; Gastroc = gastrocnemius muscle. The numbers of mice per group and tissue type are as reported for Figure 7G. For each tissue, significant effects of diet and/or sex were determined by two-way ANOVA with Tukey’s multiple comparisons test and are reported as described for Figure 8. Source data are provided as a Source Data file.