Fig. 4. Fifteen exemplary study groups suggest that perioperative weight gain increases with the perioperative amount of infused crystalloids.  8,11,16,17,44,45,155–158,198 This illustrative diagram does not consider the number of patients in each study, only contains mean values without SD, and ignores intraoperative blood loss and insensible perspiration, as not reported in all studies.  Dashed line = line of equality.