BMI mobility and obesity transitions among children in Ireland

This paper examines mobility and changes in Body Mass Index (BMI) for a sample of Irish children/adolescents across three waves of the longitudinal Growing Up in Ireland dataset. Particular attention is paid to transitions across the key BMI thresholds of overweight and obesity. Analysis is carried out by gender and by maternal education. In general, mobility is observed, with intra-generational rank-rank BMI coefficients of around 0.63 compared to coefficients of around 0.77 for the mothers of the children over the same time period. Across the distribution as a whole there is relatively little variation by gender and maternal education. However there a gender difference in terms of mobility out of obesity with the Shorrocks mobility index across categories of normal weight/overweight/obesity taking a value of 0.56 for females as opposed to 0.71 for males. This relative lack of mobility is more observed in later rather than earlier adolescence.