Beyond BMI: Waist-Integrated BMI Improves Identification of Central Dysmetabolic Obesity

Abstract Background Body mass index (BMI) does not capture fat distribution, particularly central adiposity, which is more closely linked to insulin resistance and cardiometabolic risk. We evaluated a waist-integrated anthropometric framework to identify dysmetabolic obesity beyond BMI. Methods In a retrospective observational study of 331 adults attending a metabolic clinic, an integrated body mass index (iBMI; weight × waist circumference/height) was derived. In a non-diabetic reference cohort, the relationship between iBMI and BMI was modeled, and deviation from this relationship was quantified. Associations among deviation metrics, insulin resistance, and visceral adiposity, as measured by bioelectrical impedance and dual-energy X-ray absorptiometry, were examined. Results Deviation from expected iBMI was significantly associated with visceral adiposity and insulin resistance, beyond BMI, and performed comparably to fasting glucose but better than glycated hemoglobin. Conclusions A waist-integrated BMI framework identifies central dysmetabolic obesity not captured by BMI and may enable earlier recognition of metabolic risk in clinical practice.