Background <p>One anastomosis gastric bypass (OAGB) is the most common metabolic and bariatric surgery (MBS) in Israel, recognized for its effectiveness in achieving sustainable weight loss and mitigating obesity-related diseases. The metabolic outcomes of OAGB are significantly influenced by the length of the biliopancreatic limb (BPL). The objective of this study is to determine whether tailoring the BPL length to the total small bowel length (TSBL) results in more effective weight loss compared to patients undergoing OAGB with a fixed BPL of 180&#xa0;cm. Efficacy and safety of this approach will also be evaluated, ensuring it does not lead to long-term morbidity or negatively impact patients’ quality of life.</p> Methods <p>This multicenter, prospective, randomized trial will enroll at least 200 participants undergoing OAGB across three centers. Participants, aged 18 and older, will be randomized into two groups: one group will undergo a tailored BPL length based on TSBL (40%), while the control group will receive a standard BPL&#xa0;length of 180&#xa0;cm. The primary endpoint is comparison of total weight loss after 1 and 3&#xa0;years. Secondary endpoints include postoperative complications, quality of life, and improvements in obesity-related diseases.</p> Results <p>The study will collect and analyze data as outlined in the protocol. The results will be reported upon completion of data collection and analysis.</p> Conclusions <p>The TABLE-40 study will provide robust evidence on whether tailoring the BPL to 40% of TSBL offers higher weight loss outcomes compared to a fixed-length approach in OAGB. By assessing both efficacy and safety across multiple centers, the trial aims to inform best practices in limb length selection and optimize long-term outcomes for patients undergoing OAGB.</p> Trial Registration <p>This study was registered at Clinicaltrials.gov (NCT06829381) on 29/1/2025.</p> Graphical Abstract <p></p>