Bi-directional associations of affect and physical activity in adolescents using ecological momentary assessment: Moderation by weight

Authors: SMITH, KATHRYN - University Of Southern California; MASON, TYLER - University Of Southern California; O'CONNOR, SHANNON - University Of Chicago; WANG, SHIRLENE - University Of Southern California; DZUBUR, ELDIN - Livongo Health; CROSBY, ROSS - Sanford Health; WONDERLICH, STEPHEN - Sanford Health; SALVY, SARAH-JEANNE - Cedars-Sinai Medical Center; FEDA, DENISE - University At Buffalo; Roemmich, James

Submitted to: Journal of Pediatric Psychology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/18/2020
Publication Date: 12/14/2020
Citation: Smith, K., Mason, T., O'Connor, S., Wang, S., Dzubur, E., Crosby, R., Wonderlich, S.A., Salvy, S., Feda, D.M., Roemmich, J.N. 2020. Bi-directional associations of affect and physical activity in adolescents using ecological momentary assessment: Moderation by weight. Journal of Pediatric Psychology. 46:443-453. https://doi.org/10.1093/jpepsy/jsaa121.
DOI: https://doi.org/10.1093/jpepsy/jsaa121

Interpretive Summary: Child obesity promotes negative psychological and physical health and is associated with low levels of physical activity. How a child is feeling (i.e., their affect) around the time of choosing to be physical active or not is thought to be important for the choice to engage in such behavior. The weight status (i.e., adiposity) of the child may also influence the association between a child’s affect and adiposity may alter the relationship between affect and whether physical activity occurs. Scientists at the Grand Forks Human Nutrition Research Center in collaboration with University scientists examined the associations between affect and physical activity and the extent to which adiposity moderated these associations. When youth with greater adiposity reported higher sadness and stress they evidenced less activity within the next hour. Conversely, youth with lower adiposity reported momentary sadness, they evidenced more activity within the next hour. Thus, momentary negative feelings appear to impede physical activity among youth with higher z-BMI.

Technical Abstract: Pediatric obesity confers increased risk for a host of negative psychological and physical health consequences and is reliably linked to low levels of physical activity. Affective antecedents and consequences of physical activity are thought to be important for the development and maintenance of such behavior, though research examining these associations in youth across the weight spectrum remains limited. Objective: The current study examined bi-directional associations between affect and physical activity (i.e., moderate-to-vigorous physical activity [MVPA] and total activity counts), and the extent to which weight (z-BMI) moderated these associations. Methods: Participants were drawn from a prior study of siblings (N=77; mean age=15.4±1.4 years) discordant for weight status (39 non-overweight siblings, 38 siblings with overweight/obesity) who completed ecological momentary assessment (EMA) with accelerometer-assessed physical activity. Results: Generalized estimating equations indicated z- BMI moderated trait-level and momentary associations. Adolescents with higher z-BMI who reported lower total activity reported higher sadness and stress, and when they reported momentary sadness or stress, they evidenced less MVPA and activity within the next hour. Conversely, among adolescents with lower z-BMI, higher MVPA was associated with greater sadness, and when they reported momentary sadness, they evidenced more MVPA and activity within the next hour. Conclusions: Findings indicate affective experiences surrounding physical activity differ according to z-BMI. Specifically, momentary negative affect appears to impede physical activity among youth with higher z-BMI. Further research is warranted to elucidate factors influencing these momentary associations and the extent to which these momentary associations prospectively predict weight change.