The Stayhealthy bioelectrical impedance analyzer predicts body fat in children and adults

• Published in: Nutrition research (New York, N.Y.) N.Y.), 2010-05, Vol.30 (5), p.297-304
• Main Authors: Erceg, David N, Dieli-Conwright, Christina M, Rossuello, Amerigo E, Jensky, Nicole E, Sun, Stephanie, Schroeder, E. Todd
• Format: Article
• Language: English
• Subjects: Absorptiometry, Photon; Accuracy; Adipose Tissue; Adolescent; Adult; Adults; Aged; Aged, 80 and over; Algorithms; Anthropometry - instrumentation; Anthropometry - methods; bioelectrical impedance; Bioelectrical impedance analysis; Biological and medical sciences; Body composition; body fat; Child; child nutrition; childhood obesity; Children; Correlation coefficients; Devices; DXA; Electric Impedance; equipment performance; Estimating; Fat percentage; Feeding. Feeding behavior; Female; Fundamental and applied biological sciences. Psychology; Gastroenterology and Hepatology; Humans; Hydrostatic weighing; Impedance; Male; Men; Middle Aged; nutrition risk assessment; nutritional status; portable equipment; Reference Values; reliability; Reproducibility of Results; Software; Vertebrates: anatomy and physiology, studies on body, several organs or systems; Young Adult
• ISSN: 0271-5317; 1879-0739
• DOI: 10.1016/j.nutres.2010.04.009

Abstract Bioelectrical impedance analysis (BIA) is a time-efficient and cost-effective method for estimating body composition. We hypothesized that there would be no significant difference between the Stayhealthy BC1 BIA and the selected reference methods when determining body composition. Thus, the purpose of the present study was to determine the validity of estimating percent body fat (%BF) using the Stayhealthy BIA with its most recently updated algorithms compared to the reference methods of dual-energy x-ray absorptiometry for adults and hydrostatic weighing for children. We measured %BF in 245 adults aged 18 to 80 years and 115 children aged 10 to 17 years. Body fat by BIA was determined using a single 50 kHz frequency handheld impedance device and proprietary software. Agreement between BIA and reference methods was assessed by Bland and Altman plots. Bland and Altman analysis for men, women, and children revealed good agreement between the reference methods and BIA. There was no significant difference by t tests between mean %BF by BIA for men, women, or children when compared to the respective reference method. Significant correlation values between BIA, and reference methods for all men, women, and children were 0.85, 0.88, and 0.79, respectively. Reliability (test-retest) was assessed by intraclass correlation coefficient and coefficient of variation. Intraclass correlation coefficient values were greater than 0.99 ( P < .001) for men, women, and children with coefficient of variation values 3.3%, 1.8%, and 1.7%, respectively. The Stayhealthy BIA device demonstrated good agreement between reference methods using Bland and Altman analyses.