The 25-Year National Trends in Prevalence of Metabolic Phenotypes Among Iranian Adults: From 2000 to 2025 Using Steps Studies Publisher



Abbaspour F ; Shafiee G ; Golestani A ; Birjandi SM ; Gohari K ; Sheidaei A ; Heshmat R
Source: Journal of Diabetes and Metabolic Disorders Published:2026

Abstract

Background: The increasing global burden of obesity and its metabolic complications necessitates a detailed understanding of specific metabolic phenotypes. This study investigates the 25-year trends in the prevalence of eight metabolic phenotypes that are categorized by body mass index (BMI) and metabolic health status, among Iranian adults from 2000 to 2025. Methods: This retrospective analysis utilized data from four national and sub-national cross-sectional studies based on the World Health Organization (WHO) STEPwise approach to non-communicable disease (NCD) risk factors surveillance (STEPS), conducted in Iran from 2007, 2011, 2016, and 2021. Adults aged 25-65 were classified into eight phenotypes based on BMI categories (underweight, normal weight, overweight, obese) and metabolic health status (healthy/unhealthy), defined using the National Cholesterol Education Program's and Adult Treatment Panel III (NCEP-ATP III) criteria. A smoothing spline model was applied to estimate trends from 2000 to 2025. Results: A total of 55,204 adults were included in this study. From 2000 to 2025, the prevalence of metabolically unhealthy overweight (MUOW) increased from 19.16% to 26.20%, and metabolically unhealthy obese (MUOb) from 15.07% to 21.67%, while metabolically healthy normal weight (MHNW) declined from 26.82% to 13.67%. For both genders, there was a constant increase in MUOW and MUOb, with the percentage of MUOb being nearly twice as high in females compared to males (In 2000: 19.37% vs. 10.30%, In 2025: 26.16% vs. 14.86% among females vs. males). The prevalence of MUOW (In 2000: 20.69% vs. 16.99%, among urban and rural areas, respectively, and In 2025: 26.72% vs. 23.14% among urban and rural areas, respectively) and MUOb (In 2000: 15.54% vs. 11.75%, among urban and rural areas, respectively, and In 2025: 23.26% vs. 18.76% among urban and rural areas, respectively) increased, with urban areas showing higher percentages than rural areas. Across age groups, MUOW and MUOb consistently rose over the years, peaking in the 45-54 and 55-64 age groups, while the 25-34 age group had the highest percentage of MHNW. Across provinces, MUOW and MUOb increased, while metabolically healthy underweight (MHUW), MHNW, metabolically healthy obese (MHOb), metabolically unhealthy underweight (MUUW), and metabolically unhealthy normal weight (MUNW) decreased, with metabolically healthy overweight (MHOW) showing a slight rise. Conclusion: From 2000 to 2025, a significant increase in metabolically unhealthy phenotypes, particularly MUOW and MUOb, was observed among Iranian adults, driven by a decline in metabolically healthy phenotypes. This trend underscores the need for targeted public health interventions, especially for older adults, women, and urban populations. Regional differences reflect varying cultural and socioeconomic factors. © The Author(s), under exclusive licence to Tehran University of Medical Sciences 2025.