Grant: Project Grant

Chronic stress is a key risk factor for childhood obesity. However the mechanisms by which chronic stress causes excess weight gain and differential fat distribution among children are poorly understood. The goal of the proposed study is to examine behavioural and biological pathways through which exposure to chronic stress may impact obesity risk in children. To achieve this goal, we will recruit 300 children ages 2 to 5 years from socio-economically diverse families and follow them for 3 years. We will measure children's exposure to chronic stressors, i.e., household chaos, negative life events (e.g., parental divorce), food insecurity, and parental depression, and examine how it is associated with their % body fat, waist circumference and BMI z-score, as indicators of obesity risk. We will also explore whether chronic stress leads to obesity by influencing children's behaviours, i.e., their eating, physical activity, sedentary and sleep behaviours, and/or by influencing their biologic response to stress, i.e., cortisol production. Our interdisciplinary team includes experts in childhood obesity, stress, body composition assessment, and cortisol assessment, as well as knowledge users in public health who have extensive experience engaging families, in particular low-income families. By increasing our understanding of the mechanisms through which stress "gets under the skin" and leads to obesity in children, our results will provide a much-needed basis for effective childhood obesity prevention interventions.