To assess interdependent effects of autonomous motivation to limit sugar-sweetened beverage (SSB) consumption in relation to SSB and healthy beverage (HB) intake in mother–adolescent and father–adolescent dyads.

Adopting a dyadic cross-sectional design, the actor–partner interdependence modelling (APIM) approach was used to construct and analyse two APIM for mother–adolescent and father–adolescent dyads. The first model assessed actor effects (individual’s autonomous motivation associated with his/her own beverage intake) and partner effects (individual’s autonomous motivation associated with another family member’s beverage consumption) of autonomous motivation on SSB consumption. The second model assessed actor and partner effects of autonomous motivation on HB intake.

Two Internet-based surveys were completed in participant households.

Data from a demographically representative US sample of parent–adolescent dyads (1225 mother–adolescent dyads, 424 father–adolescent dyads) were used.

In the first model (autonomous motivation on SSB consumption), actor effects were significant for adolescents, but not for parents. Partner effects were significant for mother–adolescent, but not father–adolescent dyads. In the second model (autonomous motivation on HB intake), actor effects were significant for adolescents and parents in all dyadic combinations. Regarding partner effects, adolescent autonomous motivation had a significant effect on HB intake for mothers and fathers. In addition, maternal autonomous motivation had a significant effect on adolescent HB intake. No partner effects for HB were identified for fathers.

We found significant interdependent effects of autonomous motivation in relation to SSB and HB intake in mother–adolescent and father–adolescent dyads for eleven out of sixteen pathways modelled.