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

Summary 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.