Energy expenditure in chow‐fed female non‐human primates of various weights

Abstract

ObjectiveIn this study daily energy expenditures (EE) and respiratory quotients (RQ) in female monkeys of various body weights were determined.Methods16 socially reared Bonnet Macaque female monkeys [5.5 ± 1.4 kg body weight, modified BMI (length measurement from head to base of the tail) = 28.8 ± 6.7 kg/crown‐rump length, m2 and 11.7 ± 4.6 years] were placed in the primate Enhanced Metabolic Testing Activity Chamber (Model 3000a, EMTAC Inc. Fort Lee, NJ) for 22‐hour measurements of EE (kcal/kg) and RQ (VCO2/VO2). All were fed monkey chow (4.03 kcal/g) ad‐libitum under a 12/12 hour light/dark cycle. Metabolic data were corrected for differences in body weight. Results were divided into day (8‐hours), dark (12 hours) and morning (2‐hours) periods. Data analysis was conducted utilizing SPSS (Version 13).ResultsModified BMI negatively correlated with 22‐hour energy expenditure in all monkeys (r=‐0.64, p<0.01). The large variability of daily energy intake (4.5 to 102.0 kcal/kg) necessitated division into two groups, non‐eaters (<13 kcal/kg) and eaters (>23 kcal/kg). There were also reductions (p<0.05) in both 22‐hour and dark period RQs in the "non‐eaters" in comparison to those who were "eaters". Monkeys were also classified as "lean" (modified BMI < 25) or "obese" (modified BMI > 30). The obese group had lower EE (p<0.05) during each time period and over the entire 22‐hours (p<0.05), in comparison to their lean counterparts.ConclusionThere is an association between a reduction of energy expenditure and a gain in body weight.