MULT: An allometric body mass index (ABMI) reference to assess nutritional status of multiethnic children and adolescents.

Objectives: To develop an allometric body mass index (ABMI) reference that adjusts the weight in relation to height, taking into account the changes during development (MULT ABMI reference), and to compare it with international BMI references.

Methods: The MULT ABMI reference was constructed through the LMS method, calculated with 65 644 ABMI observations of 17 447 subjects aged 5-22 years, from the United Kingdom, Ethiopia, India, Peru, Vietnam, Portugal, and Brazil. The M, S, and L curves of the MULT ABMI reference were compared with the curves of the MULT, World Health Organization (WHO), Centers for Disease Control and Prevention (CDC), International Obesity Task Force (IOTF), and Dutch Growth Study (DUTCH).

MULT: A new BMI reference to assess nutritional status of multi-ethnic children and adolescents.

Objectives: To develop a new Body Mass Index (BMI) reference (MULT) based on longitudinal data of multi-ethnic populations and to compare it to international BMI references.

Methods: The MULT BMI reference was constructed through the LMS method and the Generalized Additive Models for Location Scale and Shape (GAMLSS), with 81 310 observations of 17 505 subjects aged 0-22 years old, from the United Kingdom, Ethiopia, Peru, India, Vietnam, Brazil, and Portugal. Outlier values were removed based on weight z-scores (population level) and based on BMI z-scores using the linear mixed effects model (individual level).