At what age should BMI start being used to assess weight status in children?

Body Mass Index (BMI) is a valuable tool for assessing weight status in children, and its use is recommended to begin at 2 years of age. This is because by this age, children's growth patterns become more standardized, making BMI a reliable indicator of whether a child is underweight, normal weight, overweight, or obese.

At 2 years, children transition from being measured primarily by weight-for-length to using BMI, which takes both height and weight into account. This approach allows for better tracking of growth patterns and can help identify potential weight-related health issues early on.

Using BMI at this stage provides a practical measure for healthcare providers to communicate about weight status with parents and caregivers, facilitating early intervention if necessary. The establishment of these guidelines aligns with recommendations from health organizations, ensuring that assessments are consistent and based on evidence.

Beginning the assessment of weight status at this age helps in monitoring growth trends into later childhood and identifying those who may benefit from lifestyle interventions or further evaluation.