Dietary fibers to boost endogenous GLP-1 secretion and satiety: a scoping review

Background: Dietary fibers can stimulate endogenous glucagon-like peptide-1 (GLP-1) secretion through microbial fermentation and gut hormone signaling, potentially enhancing satiety and supporting weight management. Given the growing interest in non-pharmacological strategies to complement or support tapering of GLP-1 receptor agonist therapy, a structured overview of the human evidence is needed. Methods: A pre-registered scoping review was conducted using PubMed, Scopus and Cochrane Central. Randomized controlled trials in adults assessing circulating GLP-1 concentrations and satiety following supplementation with a single, well-defined dietary fiber were included. Fiber types were categorized based on structural characteristics. Outcomes were summarized qualitatively across fiber categories. Results: In total, 1049 papers were screened and 49 publications comprising 52 studies (total n=1,085 participants; median sample size per study=19) were included. Most studies were acute interventions (71%) and conducted in Western populations. Studies reporting increased GLP-1 showed a non-significant tendency to also report increased satiety (OR = 2.95, 95% CI: 0.87-9.98). Dextrins stood out as one of the few fiber categories showing robust effects on both GLP-1 (4 positive studies) and satiety (5 positive studies). Other fibers, such as β-glucans and mannans, showed more uniform effects on satiety or GLP-1, respectively, but did not consistently affect both outcomes simultaneously. Conclusions: Although these findings identify dextrins as a promising dietary fiber candidate for future research, the evidence remains constrained by small sample sizes, short interventions, and substantial heterogeneity. Longer-term studies in free-living conditions, including periods of GLP-1 receptor agonist tapering, are needed to capture microbiota adaptation and generate robust real-world evidence. Systematic review registration: https://osf.io/cnw4e/overview.