Normal-weight central obesity and cardiometabolic risk among adolescents and young adults in 70 countries

Abstract Body mass index (BMI) does not capture central adiposity, which raises cardiometabolic risk even at normal BMI. We estimated the prevalence of central obesity and normal-weight central obesity, and their cardiometabolic associations, among adolescents and young adults (15–29 years) in 70 countries using WHO STEPS data (2010–2023; n = 60,618). Central obesity was defined as a waist-to-height ratio ≥ 0.5, and normal-weight central obesity as central obesity with a normal BMI. Prevalence estimates were pooled using a random-effects meta-analysis; multilevel logistic regression examined associated factors and cardiometabolic associations. Pooled prevalence was 42.1% (95% CI 37.9–46.2) for central obesity and 18.8% (95% CI 16.5–21.0) for normal-weight central obesity, with substantial between-country heterogeneity (I 2 = 98.9 and 94.0%, respectively). Compared with normal BMI and no central obesity, normal-weight central obesity was associated with higher odds of hypertension (aOR 1.28, 95% CI 1.15–1.41), diabetes (aOR 1.36, 95% CI 1.08–1.71), and elevated cholesterol (aOR 1.90, 95% CI 1.70–2.13). More than two in five young people had central obesity, including nearly one in five with normal BMI; this phenotype was associated with cardiometabolic risk across income settings. Adding waist-based measures to BMI screening could help identify at-risk young people.