31st Jan 2024

Introduction: By 2030, 23% of Brazilian children aged 5-9 years are projected to be living with obesity. Childhood obesity leads to insufficient physical activity (PA), with recommendation being of a minimum of 60-min of daily moderate-to-vigorous PA (MVPA), assessable using accelerometers. A notable limitation of accelerometer-assessed MVPA lies in its dependence on cut-offs. Studies have proposed metrics to monitor PA independently of cut-offs: i) the average acceleration (ACC), ii) the intensity gradient – IG; and iii) the minimum acceleration of a portion of the day (MX). Although studies have demonstrated associations between ACC, IG, and MX metrics and health, these were predominantly focused on eutrophic children, leaving a gap in understanding of PA patterns in children with obesity. This study aims to describe ACC, IG, and MX and investigate associations between obesity-related outcomes in children with obesity. Methods: Fifty-one children with obesity (23 girls; mean age 9.3±1.6 years) participated in this investigation. Wrist-worn accelerometers (ActiGraph GT3X) were used for 7-days, and raw acceleration in milli-gravity (mg) was obtained to calculate ACC, IG, and MX metrics. Descriptive analyses were conducted, along with linear regressions to establish associations between ACC and IG with body mass index (BMI), the percentage of the 95th percentile (%BMIp95), percentage of body fat (%BF) assessed using bioimpedance, and waist-to-hip ratio (WHR). Children’s average ACC and IG was 37.4±10.9 mg and -2.19±0.16, respectively. Both M60 (179.7±79.9) and M120 (110.4±34.4) fell below what is considered MVPA. IG was negatively associated with BMI (b= -12.74; -22.42 – -3.06), %BMIp95 (b= -58.2; -103.22 – -13.17), %BF (b= -20.99; -36.69 – -5.28), WHR (b=-0.12; -0.21 – -0.03) in models adjusted for sex, age, and fat-free mass. When ACC was included in the model, no independent associations were demonstrated for ACC and IG. Conclusion: Children with obesity exhibit low levels of MX metrics. The IG may play a crucial role in improving BMI, %BMIp95, %BF, and WHR in children with obesity. Metrics indicating the most active periods suggest that young children living with obesity need to increase their most active portion of the day to meet current PA guidelines