BMIllä

BMIllä is a proposed health metric intended to complement body mass index (BMI) by incorporating additional anthropometric information to improve the estimation of cardiometabolic risk. The term appears in discussions within health informatics and Nordic epidemiology, drawing on the Finnish suffix -llä, meaning "with" or "having."

Calculation and interpretation: The BMIllä approach combines BMI with a secondary measure such as waist-to-height ratio (WHtR) or percent body fat. In its simplest form, BMIllä can be expressed as a weighted sum, for example BMIlla = α·BMI + β·WHtR, where α and β are weights determined from population data. The resulting score is typically scaled to a reference range and interpreted using risk categories that reflect both BMI and the added metric. Age- and sex-adjusted versions are used in some studies to improve calibration.

Applications: BMIllä is discussed as a tool for risk stratification in clinical settings, epidemiological research, and public health surveillance. By incorporating central adiposity or body composition, it aims to better identify individuals at higher metabolic risk who might be misclassified by BMI alone, including those with normal BMI but high abdominal fat.

Limitations and criticism: Adoption remains variable and validation is ongoing. Like BMI, BMIllä depends on accurate measurements and may be sensitive to measurement error. It can be more complex to calculate and interpret, potentially hindering comparability across settings. Calibration can vary by age, sex, and ethnicity, necessitating population-specific validation.

See also: Body mass index, Waist-to-height ratio, Obesity.