Biliopancreatic diversion with duodenal switch (BPD-DS) with a 100-cm common channel has been our treatment of choice for morbid obesity since the early 1990s. This procedure offers excellent long-term weight loss but can be associated with significant side effects.To assess the effect on clinical and nutritional parameters of increasing the common channel to 200 cm.University-affiliated tertiary care center.Patients who underwent a BPD-DS with a 200-cm common channel (study group, n = 36) were matched 1:1 for age, sex, body mass index (BMI), and main co-morbidities with patients who underwent a BPD-DS with a 100-cm common channel (control group). The strict alimentary limb was 150 cm in both groups.The mean age was 55±9 versus 53±7 years (P = .3), with 50% women and a BMI of 49±8 kg/m2 versus 50±6 kg/m2 (P = .9). Follow-up rate was 97%, with a minimum follow-up of 3 years. There were no significant differences in the remission rate of major co-morbidities between the 2 groups. At 3 years, the excess weight loss was 61±22% versus 68±18% (P = .18) and the total weight loss was 33±11% versus 38±9% (P = .055) in the study group versus control group, respectively. The study group had a lower incidence of severe protein deficiency (11% versus 19%, P = .3) and hyperparathyroidism (17.1% versus 35.3%, P = .17); required a lower amount of vitamins A and D (P<.05); and had a decreased number of daily bowel movements (2.0 versus 2.9, P = .03).In this population, BPD-DS with a 200-cm common channel offered similar remission rate of co-morbidities compared with standard BPD-DS. It was associated with similar weight loss at nadir, followed by a more significant weight regain. It might yield a lower rate of nutritional complications. Long-term randomized data are needed to detect other potential advantages.