Nutritional Care for Adults With Obesity Treated With Glucagon-Like Peptide (GLP)-1 and Dual Glucose-Dependent Insulinotropic Polypeptide (GIP)/GLP-1 Receptor Agonists: A Review of Evidence, Gaps, and Clinical Implications

Glucagon-like peptide‑1 receptor agonists (GLP‑1 RAs) and dual glucose‑dependent insulinotropic polypeptide/glucagon-like peptide‑1 receptor agonists (GIP/GLP‑1 RAs) have rapidly advanced obesity treatment, producing weight‑loss outcomes that exceed previous pharmacologic options. Despite their growing use, nutrition-focused clinical guidance has not kept pace, leaving practitioners responsible for supporting safe therapy implementation with gaps. This review summarizes current evidence on the nutritional implications of GLP‑1-based pharmacotherapy in adults with obesity, including common gastrointestinal adverse events, reduced energy intake, potential macro‑ and micronutrient inadequacies, and risks of lean mass loss. To address these gaps, we introduce an evidence-informed nutrition framework to guide health care professionals in assessment, diagnosis, intervention, and monitoring during GLP‑1 therapy. A structured literature search of peer‑reviewed studies published between 2015 and 2025 was conducted using PubMed, Embase, and Google Scholar. Across randomized controlled trials, GLP‑1 and dual GIP/GLP-1 therapies produced mean weight reductions of approximately 5% to more than 20%, with gastrointestinal symptoms frequently reported and often impacting dietary tolerance. Evidence also suggests early reductions in caloric intake and inadequate consumption of several essential nutrients, while long‑term data on micronutrient status and body composition remain limited. Findings emphasize the need for proactive, individualized medical nutrition therapy to optimize treatment tolerance, preserve lean mass, prevent nutrient deficiencies, and support sustainable outcomes. The proposed nutrition framework offers a structured clinical approach to address these challenges. Future research should focus on longitudinal dietary assessment, biomarker monitoring, and validation of standardized nutrition protocols for patients receiving GLP‑1-based obesity pharmacotherapy.