The use of bioelectrical impedance analysis to assess body composition and clinical outcomes after gastric bypass surgery.

Abstract

Body composition assessment in obese and gastric bypass patients is an important component of clinical care that remains somewhat elusive. The physiological abnormalities that occur in these populations pose unique challenges to available body composition assessment techniques. In particular, there is a lack of adequate field methods that are appropriate for clinical use (i.e. rapid, convenient, inexpensive, and accurate). Bioelectrical impedance analysis (BIA) promises to be just such a method. This thesis explores the topics of obesity and roux-en-Y gastric bypass (RYGB) surgery, the body composition changes that occur after RYGB, and methods used for assessment, with a particular focus on advancing multi-frequency BIA (MF-BIA) and bioimpedance spectroscopy (BIS) analysis.