Resting metabolic rate and body composition of Pima Indian and Caucasian children.
Since a low metabolic rate (for a given body size and body composition) is a risk factor for body weight gain and obesity is prevalent among Pima Indians, we have tested whether Pima Indian children have a low resting metabolic rate (RMR) as compared to Caucasian children. Body composition (bioelectrical resistance) and RMR were measured in 43 Pima Indian children (22 male/21 female, mean +/- s.d. 9.9 +/- 1.1 years) and 42 Caucasian children (21 male/21 female, 9.7 +/- 1.2 years). Pima children were taller (143 +/- 9 vs. 137 +/- 8 cm, P less than 0.001), heavier (48.6 +/- 15.8 vs. 32.9 +/- 7.8 kg, P less than 0.001) and fatter (39 +/- 10 vs. 24 +/- 7% fat, P less than 0.001) than Caucasians. Absolute values of RMR were higher in Pimas than in Caucasians (6234 +/- 1201 vs. 5171 +/- 715 kJ/day, P less than 0.001), but similar when adjusted for differences in body size, body composition and sex. Contrary to our hypothesis, we did not find a decreased RMR in Pima children when compared to Caucasian children. Therefore, the high prevalence of obesity in Pima children at age 10 suggests that excess energy intake and/or low levels of physical activity might be the major aetiological factor. However, this study does not exclude the possibility that a low metabolic rate might be a predisposing factor at an earlier age.
Fontvieille
A M
AM
Clinical Diabetes and Nutrition Section, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Phoenix, AZ 85016.
Dwyer
J
J
Ravussin
E
E
D001481:Basal Metabolism / Q000502:physiology*; D001823:Body Composition / Q000502:physiology*; D001827:Body Height; D001835:Body Weight; D002648:Child; D004734:Energy Metabolism; D005260:Female; D006801:Humans; D007198:Indians, North American; D016014:Linear Models; D008297:Male; D009765:Obesity / Q000208:ethnology; D044465:White People