The prevalence of overweight is increasing globally already in childhood. Eating habits are established during childhood and provide the basis for healthy lifelong weight development. Family and other environments surrounding the child heavily influence the eating habits and weight development of the child in constant interaction with the child’s own characteristics. Diet quality of preschool-aged children in Finland continues to be moderate or poor. However, more research is needed addressing multi-level modifiable factors and their interactions associating with child eating habits and weight development.

The main objective of this study was to provide deeper knowledge of the individual, family and neighbourhood-level factors associated with early childhood diet quality and weight status. This thesis used data from a prospective Steps to Healthy Development (the STEPS) Study from Finland, with 270–883 preschool-aged (ie., 2–6 years old) children and their parents.

Child diet quality and BMI were associated with all three levels: child, family and neighbourhood. Firstly, child “Food approach” appetitive traits were positively associated and “Food avoidance” appetitive traits were negatively associated with child diet quality and BMI. Secondly, both maternal and paternal diet quality and maternal self-efficacy were shown to positively associate with child diet quality. Thirdly, parental restrictive feeding practices were positively associated and parental pressure to eat was negatively associated with child BMI. Fourthly, neighbourhood socioeconomic disadvantage was negatively associated with diet quality among parents and children. Lastly, the interaction results between different levels showed that children with high “Food approach” appetitive trait and living in socioeconomically deprived neighbourhoods had a higher risk for overweight compared with their peers from affluent neighbourhoods.

In conclusion, socioeconomic inequalities between neighbourhoods should be addressed as a part of urban planning and emphasis should be put on creating environments that make healthy food choices easy, as well as guiding and empowering families to make those healthy choices.