Fitness alters the associations of BMI and waist circumference with total and abdominal fat.
OBJECTIVE
We tested the following hypotheses in black and white men and women: 1) for a given BMI or waist circumference (WC), individuals with moderate cardiorespiratory fitness (CRF) have lower amounts of total fat mass and abdominal subcutaneous and visceral fat compared with individuals with low CRF; and 2) exercise training is associated with significant reductions in total adiposity and abdominal fat independent of changes in BMI or WC.


METHODS
The sample included 366 sedentary male (111 blacks and 255 whites) and 462 sedentary female (203 blacks and 259 whites) participants in the HERITAGE Family Study. The relationships between BMI and WC with total fat mass (determined by underwater weighing) and abdominal subcutaneous and visceral fat (determined by computed tomography) were compared in subjects with low (lower 50%) and moderate (upper 50%) CRF. The effects of a 20-week aerobic exercise training program on changes in these adiposity variables were examined in 86% of the subjects.


RESULTS
Individuals with moderate CRF had lower levels of total fat mass and abdominal subcutaneous and visceral fat than individuals with low CRF for a given BMI or WC value. The 20-week aerobic exercise program was associated with significant reductions in total adiposity and abdominal fat, even after controlling for reductions in BMI and WC. With few exceptions, these observations were true for both men and women and blacks and whites.


CONCLUSIONS
These findings suggest that a reduction in total adiposity and abdominal fat may be a means by which CRF attenuates the health risk attributable to obesity as determined by BMI and WC.
Janssen
Ian
I
Department of Community Health and Epidemiology, Division of Endocrinology and Metabolism, Queen's University, Kingston, Ontario, Canada.
Katzmarzyk
Peter T
PT
Ross
Robert
R
Leon
Arthur S
AS
Skinner
James S
JS
Rao
D C
DC
Wilmore
Jack H
JH
Rankinen
Tuomo
T
Bouchard
Claude
C
D000005:Abdomen; D000273:Adipose Tissue; D044383:Black People; D001823:Body Composition; D001824:Body Constitution; D015992:Body Mass Index; D015444:Exercise; D005260:Female; D006801:Humans; D008297:Male; D010101:Oxygen Consumption; D010809:Physical Fitness / Q000502:physiology*; D014057:Tomography, X-Ray Computed; D014781:Viscera; D044465:White People