Sensitivity of bioelectrical impedance to detect changes in human body composition

Area of Science:

• Exercise Physiology
• Body Composition Analysis
• Nutritional Science

Background:

• Accurate body composition assessment is crucial for evaluating health and fitness.
• Hydrostatic weighing (HW) is a gold standard but is impractical for frequent use.
• Developing valid and accessible methods like bioelectrical impedance analysis (BIA) and skinfolds (SF) is essential.

Purpose of the Study:

• To compare lean body mass (LBM) and percent body fat (%BF) estimates from BIA and SF with HW.
• To validate BIA and SF methods before and after a 10-week diet and exercise program.
• To assess the reliability of specific BIA (Lukaski, Segal) and SF (Durnin) equations.

Main Methods:

• 17 healthy males in an experimental group underwent BIA, SF, and HW measurements.
• Measurements were taken before and after a 10-week diet and exercise regimen.
• Statistical analyses, including post hoc Scheffé contrasts and correlation coefficients, were employed.

Main Results:

• BIA (Lukaski, Segal) and SF (Durnin) equations showed no significant differences from HW for LBM and %BF.
• High and significant correlation coefficients (0.85-0.90) were found between methods for LBM.
• %BF correlations were slightly lower but remained statistically significant.

Conclusions:

• BIA using Lukaski or Segal equations is a valid method for assessing human body composition.
• SF using the Durnin equation also provides valid estimates.
• These methods effectively predict changes in body composition as measured by Siri transformation of body density.