Childhood overweight and obesity (OVOB) are global health problems associated with various adverse health, educational, and financial outcomes. As these childhood conditions continue to adulthood, they increase the risks of comorbidity and mortality among adults and create further economic and health burdens for nations. However, children born to certain immigrant groups living in high-migrant countries tend to be more affected by childhood OVOB than children of non-immigrants. As Australia has a sizable immigrant population, with almost half its inhabitants having at least one immigrant parent, OVOB among children of immigrants is a significant public health concern. Yet, existing studies on childhood OVOB in Australia and elsewhere have several limitations: they are, by and large, based on cross-sectional studies, have conceptual and methodological shortcomings, and most come from outside Australia, which makes generalising the findings to the Australian setting difficult. This thesis uses longitudinal data and improved methods to investigate parental characteristics linked to high childhood OVOB and identify at-risk groups among Australian immigrants to address the following three research questions: 1. Does parents’ place of birth influence children’s and adolescents’ longitudinal bodyweight transitions and how long they remain in each bodyweight status? 2. Do the environment in which parents were born, their attachment to their origin, and their acculturation to the host country’s ways of life impact their children's longitudinal bodyweight? 3. Does immigrant parents’ perception of their children’s weight predict their children’s longitudinal bodyweight outcome? If so, is the effect uniform irrespective of the parents’ region of birth or their acculturation characteristics to the host nation’s way of life? The main findings were published as three separate peer-reviewed papers. This research found that children of mothers born in Oceania (excluding Australia), the Middle East, and Africa regions experienced a lower probability of transferring to normal weight status from suboptimal bodyweight status or a higher chance of moving to suboptimal bodyweight status from normal weight status. In addition, children born to parents from certain immigrant groups tended to remain in suboptimal bodyweight status longer, between 2 and 17 years, than children from non-immigrant backgrounds if these immigrant children were already in suboptimal bodyweight as toddlers (published paper 1). Only children with immigrant parents were used to answer the second research question. Results showed higher bodyweight in children whose parents came from a country with unfavourable obesogenic environments. In addition, the connection to parents’ country of birth and parents’ long-term residency in Australia predicted children’s bodyweight (published paper 2). Akin to the second study, data only from children of immigrant parents were used to answer the third research question. Accordingly, children whose parents underestimated their weight at the beginning of the observation period tended to have a higher bodyweight in subsequent observations, and the increase in children’s bodyweight diminished over time. Furthermore, a much higher discrepancy in bodyweight was observed for children born to parents from the Americas than children from the North/West Europe group. However, parents’ acculturation to Australia’s environment and society had no discernible impact on the relationship between perception and subsequent bodyweight (published paper 3). The evidence found in this thesis could be used to identify at-risk children whose families need extra health support and to design culturally tailored prevention programs for childhood overweight/obesity in the country. The evidence also points to the need to start the prevention program during toddlerhood. Finally, the knowledge created from the longitudinal analysis in this thesis contributes to the understanding of disparities in overweight/obesity among children of immigrant parents and creates a path for future studies on the topic.
|Date of Award||2023|
|Supervisor||Yohannes Kinfu (Supervisor), Tom Cochrane (Supervisor) & Theo Niyonsenga (Supervisor)|