Although Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) are the most prevalent bariatric surgical procedures, high-level evidence is scarce regarding the assessment of postoperative nutritional risk in RYGB versus SG. Therefore, we performed a systematic review and meta-analysis to compare the risk of anemia and related micronutrient deficiencies after RYGB and SG. We analyzed 10 randomized controlled trials that compared RYGB and SG with reported incidence of postoperative anemia and/or anemia-related micronutrient deficiencies (iron, vitamin B , or folate).