Background: Incretin-based therapies, including glucagon-like peptide-1 (GLP-1) receptor agonists and dual GLP-1/glucose-dependent insulinotropic polypeptide (GIP) receptor co-agonists, advance obesity treatment by promoting weight loss and lowering the risk of type 2 diabetes and cardiovascular disease. Methods: This narrative review synthesizes clinical evidence to highlight the role of dietitians in obesity management when incretin-based therapies are used. Results: GLP-1 receptor agonists and dual GLP-1/GIP receptor co-agonists achieve 15–21% weight loss and reduce cardiometabolic risk. Their effectiveness and safety are optimized when integrated with medical nutrition therapy (MNT) and personalized nutrition strategies. In Italy’s aging population, the rising burden of sarcopenic obesity requires dietitian-led care to preserve fat-free mass while reducing fat mass. Dual GLP-1/GIP co-agonists show superior reductions in visceral adiposity, but effects on fat-free mass remain inconclusive, underscoring the need for dietitian oversight to prevent adverse body-composition changes. Sarcopenic obesity is associated with increased mortality and functional decline. Dietitians are uniquely qualified to ensure adequate protein intake and protect muscle during pharmacologic interventions. In Italy, role clarity in clinical nutrition remains limited; however, under national law (DM 744/94; Law 42/1999), dietitians are recognized as the professionals authorized to provide medical nutrition therapy (MNT). Conclusions: The dietitian’s expertise maximizes therapeutic efficacy, minimizes adverse effects, and safeguards long-term outcomes. Integrating dietitians into pharmacological treatment pathways is essential to optimize outcomes, ensure patient safety, and safeguard long-term metabolic health.

Background: Nutritional deficiencies are common during the first postoperative year after mini gastric bypass (OAGB/MGB). This retrospective study evaluated the adequacy of a Food for Special Medical Purposes formulated for bariatric patients in maintaining mineral and vitamin status after OAGB/MGB. Methods: Patients who underwent laparoscopic OAGB/MGB at the Nutrition Clinic of Koelliker Hospital (Turin, Italy) between January 2023 and March 2024, aged 18–65 years and taking the product at 2 sachets/day for 12 consecutive months within a structured postoperative nutritional program, were retrospectively analyzed. Anthropometric and biochemical parameters were assessed at baseline (T0), 6 months (T6), and 12 months (T12) and compared using nonparametric repeated-measures tests. Results: Twenty-five patients were included (9 males, 36%; 16 females, 64%; mean age 52.8±7.2 years; preoperative BMI 46.4±5.8 kg/m²). At 12 months, mean weight loss was 34% and excess weight loss 74%. Vitamin D deficiency (<30 ng/mL) declined significantly from 79% at baseline to 28% at T6 and 16% at T12 (p<0.001). Vitamin B12 increased significantly within the first 6 months and then stabilized (p=0.0056), with only one residual deficiency at T6. Folate levels did not change significantly (p=0.099), though deficient/borderline values fell from 40% to 4%. Hemoglobin and mean corpuscular volume remained stable. Serum iron improved significantly only at 12 months (p<0.001), while ferritin declined significantly, mainly between T0 and T6 (p=0.046), remaining above the deficiency threshold on average. Conclusions: In this real-world series, the tested product combined with structured nutritional follow-up was associated with maintenance or improvement of most micronutrient parameters during the first year after OAGB/MGB, although ferritin remained a critical parameter requiring continued surveillance.