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.

Objective: To evaluate the prevalence and the individual components of

Narrative literature reviews play a crucial role in scientific research by providing a comprehensive overview of the available knowledge on a particular topic. Unlike systematic reviews, which follow rigid methodologies, narrative reviews offer a more flexible and qualitative approach, allowing researchers to synthesize and interpret the findings of different studies. This type of review is particularly valuable in fields with a high literature diversity, as it can help identify trends, gaps, and emerging themes. A key strength of narrative reviews is their ability to provide broader context, integrate insights from diverse disciplines, and enable a deeper understanding of complex issues. They also facilitate the exploration of theories and frameworks, often leading to new hypotheses and research questions. Narrative reviews are valuable resources for practitioners and policymakers, extracting key findings that can inform practice and decision-making. However, these reviews are not without limitations. The subjective nature of narrative synthesis can introduce bias, and the lack of a standardized methodology makes the reliability of conclusions uncertain. To enhance the rigor of narrative reviews, researchers should clearly define their objectives, thoroughly document their search strategies, and critically evaluate the quality of included studies. Although narrative literature reviews may not have the same empirical basis as systematic reviews, they remain a significant tool for knowledge dissemination and theoretical exploration in scientific research. On average, only a relatively small proportion of recent scientific publications provide high levels of evidence, though the journal review process should discourage unsubstantiated conclusions in original research articles. This introductory editorial is a brief preview that aims to help read, understand, and evaluate narrative review articles.

Obeidat AA, et al. Nutr Res Pract. 2016 Aug;10(4):411-417. http://dx.doi.org/10.4162/nrp.2016.10.4.411