Background: The effect of environmental conditions on development, including growth, maturation and the fulfillment of genetic potential, can be identified through the study of the variations found among different ethnic groups in the same population. The objectives of the present study were: (i) to compare the various anthropometric and body composition parameters based on ethnicity and maturation stage in 31 Japanese and 99 Caucasian prepubescent boys and 50 Japanese and 98 Caucasian post-pubescent boys; and (ii) to assess body mass index (BMI) and its relationship with other methods of body fat evaluation.
Methods: The percentage of body fat was measured using bioelectrical impedance, near-infrared interactance and Slaughter cutaneous skinfold equations.
Results: Weight and height were statistically lower for the Japanese than the Caucasian subjects. There were no differences in body fat between the ethnic groups, but the Japanese subjects had statistically lower levels of fat-free mass. The gain in fat-free mass and the loss in body fat when attaining maturation were greater in the Caucasian subjects. The agreement of BMI with other methods was good in all of the groups but lower for the Japanese than for the Caucasian subjects.
Conclusion: Height and weight differences between the ethnic groups indicated distinct genetic potential ranges. The body fat mass did not differ between the ethnic groups, but the degree of changes when attaining maturation in the Caucasian subjects was greater. If this difference were to be maintained between the groups then years later there would be a greater accumulation of fat in the Japanese subjects.