The 2025 Diabetes Clinical Practice Guidelines, developed by the Korean Diabetes Association (KDA), aim to provide evidence-based recommendations for the diagnosis, screening, prevention, and treatment of diabetes and its complications (Supplementary Table 1).The target population for these guidelines includes people with type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM), children and adolescents with T2DM, gestational diabetes, and adults with prediabetes.The guidelines have been restructured and updated from the '2023 Diabetes Management Guideline' to serve as a comprehensive resource for a wide range of healthcare professionals involved in diabetes care, including general physicians, specialists, private practitioners, diabetes care physicians in educational institutions, nurses, nutritionists, exercise therapists, social workers, policy makers, and other professionals.By promoting evidence-based treatments, providing alternatives to risky or unnecessary interventions, and incorporating essential information on crucial aspects of diabetes care, these guidelines strive to enhance the overall quality of diabetes care in Korea, improve health outcomes, and reduce healthcare costs.Ultimately, the guidelines aim to empower healthcare professionals to make informed decisions and deliver the best possible care to people with diabetes, thereby improving their quality of life and reducing mortality rates. DIAGNOSIS AND CLASSIFICATION OF DIABETES MELLITUS1. Diagnose diabetes based on glycosylated hemoglobin (HbA1c) or plasma glucose criteria, either the fasting plasma glucose (FPG) level, 2-hour plasma glucose (2-h PG) level during a 75 g oral glucose tolerance test (OGTT), or random plasma glucose level accompanied by classic hyperglycemic symptoms [Nonrandomized controlled trial, general recommendation] Recommendation 1.1.Diagnose diabetes based on HbA1c or plasma glucose criteria, either the FPG level, 2-h PG level during a 75 g OGTT, or random plasma glucose level accompanied by classic hyperglycemic symptoms.[Non-randomized controlled trial, general recommendation] Key question Is testing HbA1c, FPG, 2-h PG during a 75 g OGTT, and random plasma glucose in the presence of hyperglycemic symptoms appropriate for diagnosing diabetes and predicting complications?

As the prevalence of type 2 diabetes mellitus continues to rise, the development of effective and sustainable prevention strategies has become a critical public health priority. Evidence from large-scale randomized controlled trials has established that lifestyle modification (LSM) programs can substantially reduce the risk of diabetes in high-risk individuals. However, routine implementation is limited by high intensity, costs, and resource requirements. We summarize major prevention trials and their effectiveness, feasibility, and limitations. Building on these insights, we introduce the Korean Diabetes Prevention Study (KDPS) as a contextually tailored model for the Korean healthcare system. The KDPS-LSM program was designed to integrate cultural and clinical relevance with practical applicability, consisting of a 6-month intensive phase of structured nutrition and lifestyle education followed by a maintenance phase to support long-term adherence. To promote sustainable change, the program incorporates the '10 habit' lifestyle messages, grounded in the transtheoretical model of behavior change, which are designed for easy implementation in daily life. This review underscores the importance of developing culturally appropriate LSM programs that balance effectiveness with feasibility, and suggests that the KDPS-LSM model could serve as a useful foundation for establishing practical diabetes prevention strategies within national healthcare systems.