We would like to thank Ds Ceyhan, Safer, and Cintosun for their interest in our article and for sharing their considerable expertise on the assessment of total body fat by bioelectrical impedance analysis (BIA). They raise several points that could have improved the precision of our measurements. They point out that ideal measurements require “…performance of the BIA at the same time of the day at all times, with no food or beverage intake for 4 hours before testing and with the bladder emptied immediately before the measurement.” They also refer to a study that indicated that the measurement of fat mass with BIA may be influenced by differences in arm length, slenderness, including arm diameter, and the relative distribution of body water (extracellular water/total body water), which may differ by ethnicity.

They cite other limitations of the use of the only 2 available sets of equations to determine total body water from BIA and the conversion of total body water to fat mass in pregnant women. Nonetheless, as noted in the article, using these equations, we found values for total body water and fat mass similar to that found in studies that measured these variables by other techniques in pregnant women.

Our study was designed to test the use of BIA in a clinical setting as a potential improvement over body mass index as an estimate of body fat. This demands a study that can be done in diverse subjects and with minimal preparation, which is not compatible with the requirements to which they have alluded.

It is very likely that controlling for the factors cited by the correspondents would have improved the precision of the study. However, not using these might cause us to miss differences but was unlikely to lead to false conclusions. Thus, we are confident that the findings we made under clinically practical conditions indicate a potential tool for future clinical studies and usage.