Comparing the Body Water Distribution in Obese and Normal Weight Adolescent Boys via Segmental Multi-Frequency Bioelectrical Impedance Analysis

Body water is the highest fractional content of body weight, except in cases of extreme obesity. The objective of the present study was to compare and evaluate the changes in total body water (TBW), and body water distribution using segmental multi-frequency bioelectrical impedance analysis (SMFBIA) in obese and normal weight adolescent boys. Seventy healthy adolescent boys of Ardabil city, Iran, (age: 15-17 years) voluntarily participated in this study. Subjects were divided on the basis of body fat percentage (%BF) value into two groups of obese (%BF > 25) and normal-weight (%BF < 15). Absolute and relative total body water, and extracellular (ECW) and intracellular water (ICW) were measured in obese (n = 36) and normal weight (n = 34) subjects using SMFBIA. Two independent markers of relative body water distribution were calculated as ECW/TBW, and ECW/ICW. The absolute values of TBW (P = 0.020), and ECW (P = 0.001) were significantly higher in the obese subjects compared to those with normal weight. TBW, as a percentage of body weight, was significantly lower in the obese subjects (P = 0.001). The ratios of ECW/ICW and ECW/TBW were significantly higher in obese adolescents (P = 0.001). This study indicates a coincident increase in absolute values of TBW with overweight and obesity in adolescent boys. It seems that increase in adipose tissue mass may contribute to extension of ECW; as ECW/TBW and ECW/ICW ratios are higher in the obese adolescent boys.