Journal of the International Society of Sports Nutrition (Dec 2025)

Measuring bioelectric impedance outputs following coffee consumption in healthy adults using an 8-electrode segmental BIA device

  • Christopher Chamberlin,
  • Aldo Lena,
  • Dimple Radia,
  • Dale Rees,
  • John Lodge,
  • James Rutherford,
  • Bruno Cesar da Silva dos Santos,
  • Bhaven Patel,
  • Shawn McLaren

DOI
https://doi.org/10.1080/15502783.2025.2528531
Journal volume & issue
Vol. 22, no. 1

Abstract

Read online

Introduction Bioelectric impedance analysis (BIA) is increasingly used to measure body composition in athletic, clinical and research settings. The reliability of BIA measurements relies on following procedures carefully. However, some practices for ensuring reliable measures may be unnecessarily restrictive. Previous research using BIA outputs as study outcome measures, has required participants to avoid coffee and caffeine-containing foods and beverages prior to measurements. The aim of this study was to determine whether BIA outputs are affected by coffee consumption at different caffeine concentrations.Methods This study used a blinded, randomized, cross-over trial design. Participants (n = 13) received one of three treatments per visit: 200 mL hot water (80°C) mixed with 5 g instant coffee, 2.5 g instant coffee with 2.5 g decaffeinated coffee, or 5 g decaffeinated instant coffee. Body composition and fluid parameters were measured over 50 minutes using a Seca mBCA 515 device.Results The treatment predictor (p > 0.05) and sex-time-treatment interaction for all outcomes was found to be non-significant (p > 0.05). The time predictor was statistically significant (p 0.01).Conclusion Changes in impedance, resistance and reactance were detected over the course of the experiment, and these changes were greater than could be explained by the technical error of measurement. However, the amount of caffeine in coffee did not affect BIA outputs. Effect sizes were small, suggesting little practical significance of drinking coffee before taking BIA measurements. Therefore, coaches, athletes, researchers and clinicians may be able to obtain reliable BIA measurements even when coffee has been consumed up to 50 minutes prior to measurements, however, fluid consumption and being adequately hydrated should still be considered.

Keywords