BMI-SDS

BMI-SDS enables comparison of individual BMI trajectories while accounting for age-specific and sex-specific growth. German clinical practice classifies overweight as BMI above the 90th percentile and obesity as BMI above the 97th percentile using national reference percentiles. BMI-SDS is calculated using the Box-Cox power transformation, median, and coefficient of variation from a German reference population. Weight and height are measured at baseline, 4 months, 8 months, and 12 months using calibrated scales and stadiometers by paediatricians. The primary outcome of fruehstArt is the change in BMI-SDS from baseline to 12 months in the intervention group compared to the control group.