Dietary Fructose and FTO Gene Polymorphism May Reduce GLP-1/GIP Combination Therapy Efficacy

While obesity and metabolic syndrome are widespread, the efficacy of incretin-based therapies, including GLP-1 receptor agonists and dual GLP-1/GIP agonists, varies significantly among individuals. Current standard-of-care often overlooks personalized factors contributing to this variability. Understanding these factors is crucial for optimizing treatment outcomes and developing more targeted interventions. This review explores how specific gene-diet interactions, particularly dietary fructose intake and fat mass and obesity-associated (FTO) gene polymorphisms, might modulate the effectiveness of these powerful metabolic therapies.

This literature review systematically examined existing research to synthesize evidence on how dietary fructose intake and FTO gene polymorphisms influence the efficacy of glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP)-based therapies. The authors conducted a narrative review, integrating findings from various studies to construct an integrated model. They focused on identifying mechanisms by which fructose consumption and FTO risk alleles could contribute to variability in incretin responsiveness, discussing clinical implications and future research directions.

High fructose consumption was found to promote a detrimental metabolic environment, characterized by hepatic steatosis, de novo lipogenesis, insulin resistance, oxidative stress, and systemic inflammation. This environment may directly contribute to reduced responsiveness to incretin therapies. In parallel, FTO risk alleles are strongly associated with increased obesity susceptibility, altered appetite regulation, and impaired leptin signaling, further exacerbating metabolic dysfunction. The review proposes a compelling integrated model:

FTO-mediated leptin resistance and fructose-induced hepatic and inflammatory stress converge to reduce the appetite-suppressive and metabolic benefits of GLP-1/GIP therapies. This convergence suggests a complex gene-diet interaction that significantly shapes treatment outcomes. Furthermore, the review highlights that these interactions could explain a substantial portion of the observed inter-individual variability in weight loss and metabolic improvements seen with GLP-1/GIP combination therapies.