Early predictors and body composition changes associated with adiposity rebound

点击翻译按钮获取中文摘要

Overweight and obesity rates are increasing in children, and overweight children have higher risk of adult obesity and therefore diseases including heart attack, stroke and diabetes. The preschool years may offer opportunities to divert children from the path to obesity, before poor physical activity and nutritional habits become firmly established. Adiposity rebound is the time in a child's life (usually around 5 to 6 years of age) when body mass index (BMI) begins to increase after a steady decline in BMI in the preschool years. Early adiposity rebound is associated with increased BMI in later life. We don't yet know whether the early adiposity rebound causes the higher BMI, or whether it is simply an early sign of an already-established pathway of behavioural and environmental risk. We need a much better understanding of predictors of early adiposity rebound and the changes that occur to determine if age at adiposity rebound is a modifiable risk factor for adult obesity. This study will document the process and timing of adiposity rebound and the changes in percent body fat and lean body mass that occur during that time. We will also determine whether risk and protective factors for early adiposity rebound and overweight at age 6 years are the same or different. We will study over 400 children on whom extensive data have been collected since birth, including period of gestation, birth weight and length. At various stages during their first two years of life, height, weight, feeding patterns and development were recorded. We will measure BMI and perform bioimpedance analysis (BIA) on these children six times between 4 and 6 years of age. BIA provides a measure of body fat and lean mass that is well accepted by children. This will help determine the relationship between changing BMI at different ages and the fat-to-lean mass ratios associated with those changes. This study is the first to consider body composition changes during adiposity rebound.