title: Ethnic differences in resting metabolic rate, respiratory quotient and body temperature: a comparison of Africans and European Australians.
abstract: OBJECTIVE
  A comparison of resting metabolic rate (RMR), respiratory quotient (RQ) and body temperature between adults of African and European descent.
  
  
  METHODS
  Twenty-nine sub-Saharan Africans (SSA; 13 men and 16 women) and thirty-two Australians of European descent (EUR; eight men and 24 women) had RMR and RQ measured by indirect calorimetry. Dual-energy X-ray absorptiometry was used to determine fat mass (FM), fat-free mass, bone mineral content (BMC), appendicular lean tissue mass and non-appendicular lean tissue mass. Total skeletal muscle mass (SMM) was predicted. Residual mass (RM) was the difference between body weight and the sum of FM, SMM and BMC. The short form of the International Physical Activity Questionnaire was used to determine habitual physical activity (PA). Tympanic in the ear temperature (IET) and forearm to fingertip temperature gradients (FFG) were monitored throughout the protocol.
  
  
  RESULTS
  The unadjusted RMR of SSA was significantly lower compared to EUR. Adjusted for age, sex, season, PA, FM, BMC, SMM and RM, this difference in RMR was still evident (mean ± SE, SSA: 4880 ± 161 kJ/d vs. EUR: 5979 ± 111, P < 0.005). The same model of adjustment also uncovered a significantly lower adjusted IET (SSA: 35.26 °C ± 0.133 vs. EUR: 35.60 ± 0.091, P < 0.05), a higher adjusted RQ (SSA: 0.86 ± 0.014 vs. EUR: 0.83 ± 0.010, P < 0.05) but no difference in adjusted FFG.
  
  
  CONCLUSIONS
  In this study, SSA had a lower RMR, higher RQ and lower IET relative to EUR Australians.
authors.affiliation: Directorate of Nutrition, Dietetics and Food Technology, School of Public Health, Curtin Health Innovation Research Institute-Biosciences, Curtin University, Perth, WA, Australia.
authors.forename: P A
authors.initials: PA
authors.lastname: Adzika Nsatimba
authors.affiliation: Directorate of Nutrition, Dietetics and Food Technology, School of Public Health, Curtin Health Innovation Research Institute-Biosciences, Curtin University, Perth, WA, Australia.
authors.forename: K
authors.initials: K
authors.lastname: Pathak
authors.affiliation: Directorate of Nutrition, Dietetics and Food Technology, School of Public Health, Curtin Health Innovation Research Institute-Biosciences, Curtin University, Perth, WA, Australia. m.soares@curtin.edu.au.
authors.forename: M J
authors.initials: MJ
authors.lastname: Soares
mesh_terms: D015502:Absorptiometry, Photon; D000273:Adipose Tissue / Q000378:metabolism; D001315:Australia; D001481:Basal Metabolism; D044383:Black People; D001823:Body Composition; D015992:Body Mass Index; D001831:Body Temperature; D001835:Body Weight; D015519:Bone Density; D002153:Calorimetry, Indirect; D015444:Exercise; D005260:Female; D006801:Humans; D008297:Male; D018482:Muscle, Skeletal / Q000378:metabolism; D056152:Respiratory Rate; D011795:Surveys and Questionnaires; D044465:White People
keywords: African; Body temperature; Muscle mass; Obesity; Resting metabolic rate; Thermoneutral zone