Tirzepatide for Weight Recurrence After Metabolic and Bariatric Surgery: A Critical Review of Direct and Indirect Evidence with Emphasis on Sleeve Gastrectomy, Nutritional Safety, and Clinical Implications

Background: Obesity is a chronic, relapsing disease associated with substantial morbidity and healthcare burden. Although metabolic and bariatric surgery (MBS) remains the most effective treatment for severe obesity, weight recurrence after sleeve gastrectomy (SG) represents a significant clinical challenge and may require additional therapeutic strategies. Tirzepatide, a dual glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptor agonist, has demonstrated substantial efficacy in obesity treatment; however, evidence regarding its use after SG remains limited. This review critically evaluates the current evidence regarding the potential role of tirzepatide in the management of weight recurrence after SG, with particular emphasis on treatment efficacy, safety, body composition, nutritional considerations, and implications for dietetic practice. Methods: A critical review of the literature was conducted using PubMed/MEDLINE, Scopus, Web of Science, Cochrane Library, and ClinicalTrials.gov databases. Evidence was analyzed according to the population studied, including direct evidence from patients after SG, data from mixed post-bariatric surgery cohorts, and indirect evidence from clinical trials involving individuals with obesity without previous MBS. Results: Available evidence suggests that tirzepatide may induce clinically meaningful weight reduction in patients experiencing weight recurrence after SG; however, direct evidence remains limited and is derived mainly from short-term retrospective studies. Findings from mixed post-bariatric populations and randomized clinical trials in individuals with obesity provide supportive but indirect evidence. Important uncertainties remain regarding long-term efficacy, treatment durability after discontinuation, effects on body composition, preservation of fat-free mass, and nutritional safety. Conclusions: Tirzepatide may represent a valuable adjunctive therapy for selected patients with weight recurrence after SG, particularly when integrated into multidisciplinary obesity management. Nevertheless, current evidence is insufficient to establish its definitive role after SG. Future prospective studies are warranted to evaluate long-term effectiveness, safety, nutritional outcomes, and changes in body composition using standardized definitions of postoperative weight recurrence.