Franny Jongbloed

183 7 FEASIBILITY AND SAFETY OF A PREOPERATIVE DIET Kidney donors Kidney donors visited the outpatient clinic at the Erasmus MC, University Medical Center Rotterdam between February 2013 and May 2014. To be eligible for the study, patients had to be between 18 and 70 years old, have a BMI ≥19, could not participate in another clinical trial in the 30 days prior to the day they were approached, and could have no known allergies to any of the ingredients in the diets. An additional exclusion criterionwas a surgery performed outside the Erasmus MC due to participation in the cross-over kidney donation program 28 . Out of 124 kidney donors, 90 were eligible to participate in the study and were approached. Initially, 45 donors gave informed consent. After the outpatient clinic visit and before the scheduled surgery, 15 donors withdrew from the study for personal or logistical reasons (Figure S3). Included dropouts after randomization were replaced until the desired number of inclusions was reached. Thirty donors were equally (n = 10) randomized into each of the three intervention groups. Bariatric surgery patients The morbidly obese patients visited the outpatient clinic at the Maasstad Hospital between March 2013 and August 2014. To participate in the study, patients had to be between 18 and 60 years of age with a BMI ≥40, could not have participated in another clinical study in the 30 days prior to the day they were approached, and could have no known allergies to any of the ingredients in the diets. Additional exclusion criteria were the presence of diabetes mellitus or morbid obesity caused by a known genetic syndrome or genetic defect. Diabetic patients were excluded to eliminate this confounding variable between the two surgery groups, as diabetic patients are not admitted to the living kidney donor program. Diabetes mellitus was defined as a fasted plasma glucose level ≥7 mmol/L as measured on two different days, or as either a fasted plasma glucose level ≥7 mmol/L or a non-fasted plasma glucose level ≥11.1 mmol/L with symptoms of hyperglycemia (such as thirst and polyuria). Out of 143 morbidly obese patients, 84 were eligible to participate and were therefore approached; 54 provided written informed consent. Sixteen patients dropped out of the study for various reasons (Figure S3). Included dropouts after randomization were replaced until the desired number of inclusions was reached. Since a high number of dropouts after randomization and start of the restricted occurred due to logistical reasons, additional patients were included in the restricted diet group. Eventually, 18 patients were randomized to the restricted diet, 10 patients to the DER-diet and 10 patients to the control group.