Body fat estimation in black South Africans: a pilot study.

OBJECTIVE

To estimate and compare the percentage of body fat in Black South Africans by underwater weighing (using three different equations), skinfold thicknesses measurements and bioelectrical impedance, in order to ascertain whether existing equations for body fat estimation apply to this racial group.

DESIGN

Blind comparison of techniques.

SETTING

Academic hospital.

SUBJECTS

22 (11 female and 11 male) healthy Black South African volunteers were studied, for hydration reasons, we present the data of 14 (six female and eight male) with a Body Mass Index between 20 and 30 kg/m2.

MAIN OUTCOME MEASURE

Percentage of body fat.

RESULTS

The comparisons indicated that the different methods give results which are in the same direction (all correlations were 0.69 or higher), but apart from the three underwater weighing equations, the methods do not give results which are the same. The 95% limits of agreement indicated a difference of no larger than four units between the underwater weighing equations, whereas the skinfold estimate could differ from the underwater weighing estimates by as much as 14 units, and bio-impedance could differ from the underwater weighing estimates by as much as 18 units.

CONCLUSION

From this pilot study we conclude that skinfold thickness measurements and bioelectrical impedance are unproblematic means for estimating percentage of body fat. Existing equations for body fat estimation by underwater weighing and skinfold thickness measurements seem to be applicable to this racial group, but we suggest that further research should be conducted to develop, ethnic-specific equations within racial parameters.