DEXA or BMI: clinical considerations for evaluating obesity in collegiate division I-A American football athletes.
OBJECTIVE
To evaluate the relationship between body mass index (BMI) and %body fat (%Fat) in collegiate football athletes (FBA) compared with age-matched/gender-matched general population volunteers (comparison group, CG) and compare body composition and overweight/obese frequencies by BMI between FBA and CG.


METHODS
Cross-sectional.


METHODS
Two Division I-A (D-IA) universities in Texas. Integrative Health Technologies (San Antonio, Texas) laboratory.


METHODS
Football athletes (n = 156, 20.0 ± 1.3 years, 185.6 ± 6.5cm, 103.3 ± 20.4 kg). Comparison group (n = 260, 21.5 ± 2.7 years, 179.0 ± 7.6 cm, 86.3 ± 20.9 kg).


METHODS
Body mass index and bone densitrometry (DEXA) body composition were assessed. Regression was used to predict %Fat from BMI in CG and FBA. To compare %Fat, fat mass (FM), fat-free mass (FFM), and weight (WT) between CG, FBA, linemen, and non-linemen, 1 × 4 analysis of variance was used. Chi-square analysis was used to compare the frequency of BMI ≥25 between groups.


RESULTS
Body mass index differently predicted %Fat for CG (r = 0.643, SE = 6.258) and FBA (r =0.769, SE = 4.416). Body mass index cutoffs for overweight/obese corresponded to the following %Fat in each group [BMI ≥25 = 19.9% (CG) and 11.1% (FBA); BMI ≥30 = 27.3% (CG) and 20.2% (FBA)]. Football athletes had significantly higher WT, BMI, FFM, and frequency of BMI ≥25 with lower %Fat and FM than CG (α < 0.05). Linemen had the highest WT, BMI, FFM, %Fat, and frequency of BMI ≥25.


CONCLUSIONS
The relationship between BMI and %Fat differed between CG and FBA. Using current BMI thresholds for obesity in FBA may result in misleading inferences about health risk.
Applied Exercise Science Laboratory, Texas A & M University, College Station, Texas 77843-4243, USA. bradlambert@hlkn.tamu.edu
Brad S
BS
Lambert
Jonathan M
JM
Oliver
Gilbert R
GR
Katts
John S
JS
Green
Steven E
SE
Martin
Stephen F
SF
Crouse
D015502:Absorptiometry, Photon; D000293:Adolescent; D000328:Adult; D056352:Athletes / Q000706:statistics & numerical data*; D001823:Body Composition; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D005538:Football / Q000502:physiology*; D006801:Humans; D008297:Male; D009765:Obesity / Q000175:diagnosis* / Q000453:epidemiology; D013334:Students / Q000706:statistics & numerical data; D013781:Texas / Q000453:epidemiology; D055815:Young Adult