Understanding family dynamics of obesity: Do parents and children lose and gain weight together?

Background

Obesity is prevalent among children and adults. Yet, understanding the relationship between parent and child weight trajectories is limited.

Objective

(1) Examine the association between parent/child undesirable body mass index (BMI) category change. (2) Assess whether parental BMI category predicts child modified BMI z-score (mBMIz) annual change.

Methods

We conducted a cross-sectional study of weight trajectories of 3821 parent–child dyads between March 2020 and December 2021 within the NYC Health + Hospitals system. Undesirability of child and parental BMI category change and the magnitude of mBMIz change by parental BMI are analysed.

Results

Of 3821 children (mean [SD] baseline age, 9.84 [3.51]), 1889 were female. Of the 3220 parents (mean [SD] baseline age, 39.9 [8.51]), 2988 were female. Most children (53.52%) and parents (81.94%) presented with overweight and obesity. Undesirable BMI change in children was associated with concordant change in parents (adjusted OR: 1.7, 95% CI [1.45, 2.01], adjusted p < 0.001). Children of parents with obesity (adjusted coef: 0.076, 95% CI [0.004, 0.147], p < 0.038) and severe obesity (adjusted coef: 0.1317, 95% CI [0.024, 0.239], adjusted p < 0.016) demonstrated greater change in mBMIz than those of parents with normal weight or underweight.

Conclusion

Parents and children have concordant weight trajectories, and public health interventions targeting both populations are essential.