Extended Data Figure 2. BMRs for humans, chimpanzees and orangutans.

Available BMR data for chimpanzees^15,16 are primarily from juveniles (age: 2 months to 15 years), and are shown here against comparably aged humans¹⁴ (3–18 years). Humans have greater BMRs than chimpanzees in a general linear model of ln-transformed BMR and mass controlling for age and sex (P < 0.001; Supplementary Table 3). Note that in humans (but not chimpanzees), males have greater BMRs for a given body mass, reflecting their greater proportion of FFM (that is, lower body fat percentage). The available data for orangutan BMR consists of one juvenile individual¹⁶ (no age reported, mass 16.2 kg). Resting metabolic rates (RMRs; kcal day⁻¹), measured in alert orangutans while sitting¹⁷, are also shown. The top of the bar indicates the measured RMR for those individuals, and the bottom square indicates estimated BMR bas ed on those measurements¹⁷, assuming BMR = 0.8RMR. No BMR data are available for gorillas. Symbols marked with black circles are males. Allometric regressions shown for Pan (y = 100.17x^0.65) and Pongo (y = 218.61x^0.37) and were used to estimate BMR for the adult cohorts in Table 1. Human BMR in Table 1 was estimated from published, sex-specific predictive equations for adults²⁷.