Document Type
Article
Abstract
Background
Mediation analyses provide insight into both ‘pieces’ of the mediation chain; they allow us to look into the ‘black box’ that is behavior change. They allow researchers to better understand the ‘how’ of an intervention’s effects and/or the ‘why’ behind why an intervention worked or did not work. The lack of publications in pregnant populations highlights the need for additional studies to be conducted and published. The purpose of this study is to examine the psychosocial mediators of physical activity and dietary outcomes in a sample of pregnant women with overweight or obesity participating in the Health in Pregnancy and Postpartum (HIPP) randomized controlled trial.
Methods
Participants took part in a behavioral physical activity and dietary intervention. At baseline and 32 weeks gestation, participants completed a survey assessing demographics, social support, self-efficacy, and self-regulation; the SenseWear Armband and the Automated Self-Administered 24-h dietary recall were used to measure physical activity and dietary outcomes. A multiple mediator model, using SPSS PROCESS macro was used to examine psychosocial mediators of changes in physical activity and dietary outcomes.
Results
Results showed that self-regulation (self-monitoring) was a significant mediator of increases in diet quality and decreases in total caloric intake. None of the variables examined were significant mediators of changes in moderate to vigorous physical activity or sedentary behavior.
Conclusions
This study contributes to the very limited literature examining psychosocial mediators of change in physical activity and dietary outcomes in pregnant women. Results from this study highlight the importance of self-regulation, and more specifically self-monitoring, in changing dietary outcomes. Future behavioral interventions in pregnant populations should continue to incorporate self-regulation activities like self-monitoring, goal setting, rewards, and problem solving. Work remains in better understanding how interventions change physical activity outcomes in pregnant populations. Such efforts will help to understand how interventions exert their effects and will ultimately allow for the creation and implementation of more targeted and effective behavioral interventions in pregnant women.
Digital Object Identifier (DOI)
Publication Info
Published in BMC Pregnancy and Childbirth, Volume 26, Issue 531, 2026.
Rights
his article is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License, which permits any non-commercial use, sharing, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if you modified the licensed material. You do not have permission under this licence to share adapted material derived from this article or parts of it. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by-nc-nd/4.0/.
APA Citation
Baruth, M., Wilcox, S., Liu, J., & Schlaff, R. (2026). Psychosocial mediators of a physical activity and dietary intervention in pregnant women with overweight or obesity. BMC Pregnancy and Childbirth, 26.https://doi.org/10.1186/s12884-025-07780-0