Summary Childhood overweight and obesity are an important public health problems. Children with overweight or obesity have an increased risk of developing several short- and long-term comorbidities as well as obesity in adulthood. Due to the fact that obesity is difficult to reverse, early prevention of childhood overweight and obesity is crucial. Although during the recent years a stabilization in the prevalence rates has been observed in the Netherlands, large and growing ethnic inequalities in overweight and obesity prevalence exists. Whereas among children of Dutch descent the prevalence rates of overweight and obesity have stabilized, at the same time, the rates for children of Moroccan or Turkish descent have been increasing. An increasing amount of evidence suggests that the early life period is a critical period in the development of overweight and obesity. Early growth patterns, i.e. development in weight and body mass index (BMI) during infancy and early childhood are strongly associated with later overweight and obesity risk. Feeding during the first years of life is suggested as one of the key determinants of growth with potential long-term health consequences. The main aim of this thesis was to investigate associations of infant milk- and complementary feeding (CF) practices as well as toddler dietary patterns with weight-related outcomes during early childhood. A secondary aim was to investigate these associations among different ethnic populations in the Netherlands at varying risk for overweight. For this aim, data from 3 Dutch population studies in children was used; the Amsterdam Born Children and their Development (ABCD) cohort, the TIBET study and the GECKO Drenthe cohort. The findings from this thesis suggest that infant feeding factors, such as the duration of EBF and the timing of CF, may be important for the prevention of childhood overweight. However, the effects were found to vary across subpopulations according to certain maternal characteristics. Therefore, targeted interventions ...