There is relatively limited knowledge about the development of child eating patterns and how they may contribute to excess weight gain in early life. Particularly scarce are genetically informative studies that addressed environmental and genetic influences which can be challenging to disentangle. A review of this literature can help identify ongoing themes in the field and may stimulate new ideas for future research. The purpose of this paper is to provide an overview about how select environmental factors (e.g. the portion size of foods) and parental feeding practices (e.g. dietary restriction) can affect children's eating behaviour and weight status. The second part of the review explains in more detail the types of studies that can be employed to assess genetic influences (e.g. heritability estimates) on child food intake and body weight and composition. The review closes with suggestions for future research emphasizing the importance of collaborations among investigators from different disciplines to further elucidate gene-environment interactions in the domains of child eating behaviour and obesity.