Age at adiposity rebound and body mass index trajectory from early childhood to adolescence; differences by breastfeeding and maternal immigration background

Objective: This paper aims to assess association between breastfeeding and maternal immigration background and body mass index development trajectories from age 2 to 16years. Methods: A cohort of children born in Stockholm during 1994 to 1996 was followed from age 2 to 16years with repeated measurement of height and weight at eight time points (n=2278). Children were categorized into groups by breastfeeding status during the first 6months of life and maternal immigration background. Body mass index (BMI) trajectories and age at adiposity rebound were estimated using mixed-effects linear models. Results: Body mass index trajectories were different by breastfeeding and maternal immigration status (P-value<0.0001). Compared with exclusively breastfed counterparts, never/short breastfed children of Swedish mothers had a higher BMI trajectory, whereas never/short breastfed children of immigrant mothers followed a lower BMI trajectory. Ages at adiposity rebound were earlier for higher BMI trajectories regardless of maternal immigration background. Conclusion: Differences in BMI trajectories between offspring of immigrant and of Swedish mothers suggest a lack of beneficial association between breastfeeding and long-term BMI development among children of immigrant mothers. Given the relation between long-term BMI development and risk of overweight/obesity, these differences challenge the notion that exclusive breastfeeding is always beneficial for children's BMI development and subsequent risk of overweight/obesity.