Sex Differences in the Association between Household Chaos and Body Mass Index z-Score in Low-Income Toddlers.

Associations between household chaos and childhood overweight have been identified, but the mechanisms of association are not clearly established in young children, with some studies linking higher chaos to increased obesity risk, whereas other studies link higher chaos to lower obesity risk. Given the lack of consistent findings and early sex differences in vulnerability to chaos, we examined child sex as a moderator of the chaos-child overweight association. We also tested these associations with self-regulation, as self-regulation has been implicated in understanding the chaos-obesity risk association in low-income toddlers. Parent-reported household chaos and observed child self-regulation were collected at baseline [ = 132; age 23.0 months (standard deviation 2.8)]. Children's body mass index z-score (BMIz) was measured at 33 months. Multivariate linear regression models were used to assess whether child sex moderated the chaos-BMIz association. A three-way interaction between chaos, child sex, and self-regulation was also tested. Child sex moderated the chaos-BMIz association ( = -0.11,  = 0.04) such that chaos was positively associated with BMIz among boys ( = 0.12,  = 0.003), but unrelated in girls ( = 0.01,  = 0.78). A three-way interaction with self-regulation indicated that a positive chaos-BMIz association existed only for boys with average ( = 0.12,  = 0.004) and low ( = 0.22,  < 0.001) self-regulation. Boys with poor self-regulation may be particularly vulnerable to obesogenic effects of chaotic households.