C. H. VAN WIJK
direct comparisons of women and men’s results.
Future studies need to include participants that are more re-
flective of the general population distribution (with regard to
age, gender, employment status, education, and so forth), as
well as external (vs self-reported) controls for medical and
lifestyle risk factors (e.g. hypertension, diabetes, exercise and
nutrition).
To conclude: in the presence of a wide weight spectrum
among the participants, and the absence of history of known
medical risk factors, the lack of significant BMI-GP interaction
suggests that there is no real evidence of body mass signifi-
cantly affecting GP performance among younger adults.
Slowed performance on the GP (in the presence of elevated
body mass) would thus probably be due to neurological disease
processes, rather than body fat percentage.
Thus, the effect of BMI may generally be discounted when
interpreting GP results until further corroboration of the inter-
action has been reported.
Acknowledgements
I wish to acknowledge Chesray Hans-Arendse, Sadia Edross,
Marilize Willers and Ruby Muller who assisted in the admini-
stration of the GP, and Aileen van der Spuy who did the BMI
measurements.
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