Can health nurses’ assessments of weight status in the first year of life predict well-being in the first years of school?

Background Early life represents a critical period for shaping long-term health outcomes, with early interventions playing a significant role in promoting well-being. This study aimed to investigate whether infant weight status could predict concerns of health and well-being in the first years of school using health nurse data. Methods Data from the Danish Child Health Database collaboration, included 54 917 children and families who received home visits at 8–10 months and school examinations by health nurses during their first years of school. Well-being was assessed by health nurses based on seven indicators, covering language skills, motor development, emotional well-being, and peer relationship problems. Weight status was measured using BMI z-scores and tested categorical, linear and using restricted cubic splines to explore predictive performance. Model performance was evaluated through visualization of restricted cubic splines and by Area Under the Curve (AUC). Results Infant weight status at 8–10 months showed poor predictive performance (AUC < 0.6) across all indicators of well-being in first years of school. While certain weight categories, especially severe thinness, overweight, and obesity, were linked to specific concerns like language skills and motor development, these associations had wide confidence intervals. Conclusion Infant weight status, while potentially indicative of later health concerns, was not a reliable predictor of health nurse concerns of well-being in the early school years. The findings demonstrated that the predictive performance remained limited in serval models, indicating that infant weight alone may not capture the complexity of factors contributing to later well-being by health nurse records.