A study was conducted on 43 grade III obese women submitted to bariatric surgery. Anthropometric and bioimpedance (800 mA-50 kHz) data were obtained during the preoperative period and 1, 2, 3, and 4聽y after surgery. BIVA was performed by plotting resistance and reactance values corrected for body height (R/H and Xc/H, Ohm/m) as bivariates on the RXc graph. BIVA software was used to plot the vectors of the RXc plane.
Surgery promoted changes in body composition, with a reduction of fat mass and of fat-free mass. During the postoperative period, the vectors demonstrated migration to the right lower quadrant of the graph, corresponding to the classification of cachexia and water retention.
Weight loss due to surgery results in an important reduction of fat-free mass characterized by the position of most individuals in the cachexia quadrant throughout the postoperative period.