Analysis of body composition among children and adolescents - a cross-sectional study of the Polish population and comparison of body fat measurement methods

Objective: The first aim of the present study was to analyze the body composition of Polish children ages 7-17 years old to add to the current body of literature. The second aim was to compare two body fat measurement methods (bioimpedance vs. Slaughter equation) on the abovementioned population. Methods: Height (cm) and weight (kg) of 308 (161 males and 147 females) participants, ages 7-17, were measured, and body mass index (BMI) scores were calculated. Skinfold thickness (SFT) was measured for the triceps, subscapular, abdominal, suprailiac, thigh, and medial thigh skin folds on the left side of the body. Fat mass, fat percentage in the whole body (%BF), fat-free mass, and total body water were assessed using bioelectrical impedance analysis (BIA). Results: In the present sample, 29.5% of males were overweight, and 11.3% of these were obese. Among females, 27.2% were classified as overweight, and 6.8% of these were obese. Males had a higher total body water (median = 27.25 vs. 24.8 kg, p<0.001) and fat-free mass (median=37.25 vs. 33.90 kg, p<0.001), while females showed a higher total body fat percentage (median=22 vs. 14.55%, p<0.001) and fat mass (median=9.1 vs. 5.9 kg, p<0.001). %BF calculated using Slaughter equations overestimated those obtained by BIA in both genders (p<0.0001). Conclusions: The percent of youths classified as overweight and obese has increased in Krakow (Poland). Calculation of body fat percent derived from bioimpedance provides better estimates than the use of Slaughter equations, which tended to overestimates the values.