Examining the interdependence of parent-child dyads: Effects on weight loss and maintenance

Abstract

Background: This study aimed to further elucidate correlated weight changes in parent-child dyads enrolled in family-based treatment (FBT) by modeling the interdependence of weight changes during treatment.

Methods: Parent-child dyads (n = 172) with overweight/obesity (child mean zBMI = 2.16 ± 0.39; parent mean BMI = 37.9 ± 9.4 kg/m2 ) completed 4 months of FBT and were randomized to one of three 8-month maintenance interventions (Social Facilitation Maintenance [SFM]-high dose, SFM-low dose or control). Weight/height was measured at 0, 4 and 12 months. Structural equation models simultaneously estimated the effect that an individual had on their own (actor effect) and on one another's (partner effect) weight-status across time using the actor-partner interdependence model.

Results: Actor paths were significant over time for parent and child. Partner paths were significant for child zBMI predicting parent BMI at 4 and 12 months. Maintenance condition moderated actor/partner paths in the model.

Conclusions: Child weight change may motivate parents to make environmental and behavioural changes that impact their own weight.

Trial registration: ClinicalTrials.gov Identifier: NCT00759746.

Keywords: actor-partner interdependence model; family-based treatment; long-term weight maintenance; obesity.

© 2020 World Obesity Federation.

Figures

Figure 1.

Structural equation model of basic saturated Actor Partner Interdependence Model (APIM) of parent-child weight-status from baseline (month 0) to post-Family-based Behavioral Treatment (month 4). Note. a1 = child actor path; a2 = parent actor path; p21 = child partner effect on parent; p12 = parent partner effect on child. C-zBMI = child body mass index z-score; FBT = Family-based Behavioral Treatment; P-BMI = parent body mass index. All modeled paths are presented with corresponding standardized beta coefficients and standard errors in parentheses. Significant model paths and estimates are presented in bold. Exogenous variables (P-BMI and C-zBMI at time 1) were allowed to covary, and error terms are shown to lower right of the variables.

Figure 2.

Structural equation model of actor partner interdependence model (APIM) of parent-child weight-status from post-Family-based Behavioral Treatment (FBT) (4-months) to post-maintenance (12-months) with maintenance condition as moderator of actor and partner paths. Note. C-zBMI = child body mass index z-score; FBT = Family-based Behavioral Treatment; P-BMI = parent body mass index; SFM-H = Social Facilitation Maintenance - High dose; SFM-L = Social Facilitation Maintenance – Low dose. All paths of the actor partner interdependence model (APIM) were estimated with interactions (SFM-L as reference group); only significant paths are shown in the figure, and standardized beta coefficients with standard errors are in parentheses. Exogenous variables (P-BMI and C-zBMI at time 1) were allowed to covary, and error terms are shown to the immediate right of the variables, with actor path estimates to the right of those.