Body mass index as a predictor of body fat in athletes
Srdic Biljana1, Karaba-Jakovljevic Dea2, Stokic Edita3
1
Department of Anatomy, Medical Faculty, Novi Sad, SCG 2Department of Physiology, Medical Faculty, Novi Sad, SCG
3
Department of Endocrinology, Diabetes and Metabolic Disorders, Institute for Internal Medicine, Novi Sad, SCG
Introduction
Body mass index (BMI) has been widely accepted as a parameter of nutritional status and predictor of risk of obesity
related diseases. Previous studies showed that although it strongly correlates with body fat mass it is not exact measure
of body fatness, especially in athletes who can be overweight without being obese. The aim of this study was to explore
relationship between BMI and body fat in athletes from different sports.
Methods
The study group was consisted of 175 athletes (77 basketball players, 43 volleyball players, 18 handball players, 12
boxers and 25 rowers). Body mass, body height, 7 body circumferences (upper arm, forearm, chest, waist, hip, proximal
thigh, mid thigh and calf), and 10 skinfold thicknesses (triceps, biceps, chest, subscapular, midaxillary, suprailiac,
supraspinal, abdominal, thigh and calf) were measured. BMI was calculated for all subjects and percentage of body fat
(FAT%) was estimated using equations of Forsyth&Sinning and Jackson&Pollock.
Results
Using criteria given by WHO most athletes were normal weight (BMI:18.5-24.9 kg/m2). Underweight (BMI<18.5 kg/m2)
2
was found only in basketball players (5.19%) and overweight (BMI:25-29.9 kg/m ) was present in 50% of handball
players, 27.27% boxers, 20.78% of basketball players, 12% of rowers and 9.30% of volleyball players, while11.11% of
2
handball players were considered as obese (BMI≥30 kg/m ) (figure1). Overweight athletes had higher values of body fat
comparing with normal weight subjects but only significant difference was found in rowers (figure 2).
100
18
90
16
80
14
70
BMI(kg/m2)
60
%
*
12
BMI(kg/m2)
10
50
<18,5
40
18,5-24,9
8
18.5-24.9
30
25-29,9
6
25-29.9
20
>30
4
>30
FAT%
<18,5
2
10
0
0
boxers
handball volleyball
players
players
rowers
basketball
players
Fig. 1: BMI values in examined subjects
boxers
handball volleyball
players
players
rowers
basketball
players
Fig. 2: Body fat (FAT%) in athletes with different BMI values
Significant correlation between BMI and FAT% was found in rowers, handball players and volleyball players. All athletes
classified as overweight or obese had significantly higher values of waist circumference comparing with normal weight
subjects of the same sport. All overweight and obese subjects also had higher values of subscapular and abdominal
skinfold thicknesses, except handball players. Overweight and obese boxers, basketball players, rowers and volleyball
players had significantly higher values of upper arm-, forearm-, thigh- and hip circumference. Basketball players, boxers
2
and volleyball players with BMI≥25kg/m had significantly higher values of chest- and calf circumference compared to
normal weight athletes, while all overweight athletes, except volleyball- and handball players had significantly higher
values of supraspinal-, suprailiac- and midaxillary skinfold thicknesses.
Discussion/Conclusion
Our results confirmed that using of BMI in body fat mass estimation in athletes is limited. BMI correlated with body fat but
not in all groups of athletes. Significantly higher values of waist circumference and trunkal skinfold thicknesses in
examined athletes with higher BMI values could suggest it’s importance in prediction of trunk adiposity which carries
greater risk.
References
Obesity-Preventing and menaging the global epidemic (1997).Report of WHO consultations on obesity. Geneve, 7-17
Bray GA (1998). Contemporary Diagnosis and Management of Obesity. Published by Handbooks in Health Care Co,
Newtown, Pennsylvania, USA:9-131
Heyward HV, Stolarczyk ML.(1996). Applied Body Composition Assessment. Human Kinetics: 4-19
Ohno M, Nishisaka S, Ikeda Y (1998). Body mass index, percent body fat and normal weight obesity. Int J Obes Relat
Metab Disord Aug; 22 Suppl 3: S194