Background/Objectives: Metabolic syndrome (MetS) is a complex disorder characterized by insulin resistance (IR), central obesity, atherogenic dyslipidemia, and higher glucose levels. It increases the risk of cardiovascular disease (CVD) and type 2 diabetes mellitus (T2DM), imposing an economic burden on the healthcare system. However, the historical origins of MetS as well as the development and evolution of its definitions have not been conclusively documented in the literature. This study seeks to enhance the understanding of the developmental trends of MetS during the preceding two decades, placing particular emphasis on the definition, diagnosis and prevalence. Methods: An extensive search was performed from 1920 to 2023 across prominent scientific research engines, including Scopus, PubMed, MDPI, and others. Results: Despite advancements, many aspects of MetS remain inadequately understood. As the understanding of the nature and pathophysiology of MetS progresses, the development and refinement of its diagnostic criteria, and assessment and treatment guidelines will continue. Additionally, there exists significant variation in the global prevalence of metabolic syndrome, ranging from 14 to 39%. This prevalence is projected to increase due to the adoption of less healthy dietary patterns and sedentary lifestyles. The observed disparities in metabolic syndrome prevalence can be attributed to multiple factors, including demographic characteristics. Furthermore, the lack of a standardized definition across studies also contributes to the variation in reported prevalence rates. Conclusions: Further studies focusing on the standardization of the MetS definition across different research are crucial. The establishment of consistent criteria would enhance the reliability and validity of research findings, enabling more meaningful comparisons and interpretations.

Polysaccharide-based nanocarriers offer a novel delivery system for improving the stability, controlled release, and biological functionality of plant-derived bioactive materials. Olive leaf extract (OLE), rich in polyphenolic compounds with antioxidant and other bioactive properties, is limited by low stability and bioavailability. In this study, OLE-loaded alginate–chitosan nanoparticles were prepared using ionotropic gelation–polyelectrolyte complexation (IG-PEC) method, and their physicochemical properties, cytotoxic behavior, and potential prebiotic effects were evaluated. The resulting nanoparticles (232–237 nm) exhibited uniform spherical morphology, negative zeta potentials, and improved colloidal stability. Free OLE demonstrated concentration-dependent and selective cytotoxicity toward A549 and MCF-7 cancer cells, while exhibiting lower toxicity toward normal fibroblasts. In contrast, unloaded and OLE-loaded nanoparticles (1X, 2X) showed low cytotoxicity, suggesting superior biocompatibility of the polysaccharide nanocarrier. Notably, cultures supplemented with OLE-loaded nanoparticles showed a trend toward higher probiotic growth compared to free OLE, indicating a potential prebiotic effect and improved microbial tolerance to polyphenols during extended exposure. These findings highlight the advantages of polysaccharide-based nanoencapsulation for both stabilizing bioactive materials and supporting favorable microbial responses. The developed OLE nanocarriers may serve as a promising platform for nutraceutical, biomedical, and functional food applications.

Starch cross-linking and pre-gelatinization reduced protein quality and IGF-I responses in wheat-based diets, while their effects were minimal in corn and millet. Gluten-free cereals maintained protein quality despite functional starch modification.