Accelerometer-Based Physical Activity and Shape and Weight Concerns Among Youth With Overweight and Obesity: A Pilot Exploratory Ecological Momentary Assessment Study.

Background: A bidirectional association between shape and weight concerns (SWC) and physical activity (PA) has been previously documented. This relationship may be particularly salient among youth with overweight/obesity, given that social marginalization of larger bodies has been associated with elevated SWC and barriers to PA. This pilot study explores reciprocal relationships between momentary SWC and accelerometer-assessed PA behavior. Methods: Youth with overweight/obesity ( N  = 17) participated in a 14-day ecological momentary assessment protocol, during which they were prompted to respond to questions about SWC several times per day. They also continuously wore Actiwatch 2 accelerometers to capture light and moderate-to-vigorous PA behavior. Results: Hierarchical linear modeling revealed a unidirectional association between SWC and PA, whereby after engaging in a higher duration of PA, participants reported lower SWC. SWC did not predict subsequent PA. Conclusion: The findings support a negative temporal relationship between PA and SWC. While further work is needed to replicate and extend these preliminary findings, they may suggest that PA acutely benefits SWC among youth with overweight and obesity.