Validity of the leg-to-leg bioimpedance to estimate changes in body fat during weight loss and regain in overweight women: a comparison with multi-compartment models

Abstract

To investigate changes in body composition and the validity of the leg-to-leg bioimpedance (LTL) method to measure body fat during active weight loss (WL) and weight regain (WR). Longitudinal, 12-week weight loss intervention (3.3–3.8 MJ/day) and subsequent follow-up at 1 year. Fifty-eight adult women aged between 24 and 65 years (mean age: 46.8±8.9 years) and with a body mass index (BMI) 25 kg/m² (mean BMI: 31.6±2.5 kg/m², range=26.0–48.2 kg/m²) participated in the study. Fat mass (FM) was measured at baseline, 12 weeks, 24 weeks and 52 weeks using three- and four-compartment (4-C) models, air displacement plethysmography (ADP), deuterium dilution – total body water (TBW), dual-energy X-ray absorptiometry (DXA), skinfold thickness (SFT), tetrapolar bioelectrical impedance analysis (T-BIA) and LTL. At the end of the weight loss programme, subjects lost 9.9±3.5 kg weight (PPbias±2s.d.=0.51±3.26 kg; WR_bias±2s.d.=−0.25±2.30 kg) was similar to ADP, DXA and TBW in both phases but it was better than T-BIA (WL_bias±2s.d.=0.17±7.90 kg; WR_bias±2s.d.=−0.29±7.59 kg) and skinfold thickness (WL_bias±2s.d.=2.68±6.68 kg; WR_bias±2s.d.=−0.84±3.80 kg). Weight loss and regain were associated with minimal changes in lean tissue as measured using multi-compartment models. The LTL system is a useful method to measure body composition changes during clinical weight management programmes.