Background This study investigated the relationship between growing up in a violent home and developmental trajectories of body mass index (BMI) in a cohort of adolescents followed longitudinally from 1996 to 2003–4.

Methods 6043 girls and 4934 boys aged 9–14 years in 1996 who reported height and weight at least two times and whose mothers completed intimate partner violence (IPV) questions at the 2001 Nurses' Health Study. Main exposure was experiencing the first family violence during early (0–5 years) or later (6–11 years) childhood, based on mother's year-specific exposure of IPV and the birth year of each participant. Mother's report of IPV was ascertained by the abuse assessment screen. Four distinct BMI trajectory groups were estimated from age-specific BMI (age 12–20 years), using general growth mixture modelling.

Results Four distinct BMI trajectories were identified separately for girls and boys: healthy growth; healthy to obese; steady overweight and consistently obese. Compared with boys not exposed to violence at home, boys raised in violent homes before 5 years were at increased risk of being in the consistently obese (OR =2.0; 95% CI 1.2 to 3.5) and steady overweight (OR 1.4; 95% CI 1.1 to 1.9) groups after adjusting for confounders. Girls raised in violent homes were more likely to be in the steady overweight group, but associations did not maintain statistical significance after adjusting for confounding.

Conclusion These data link children's exposure to domestic violence to a risk of unhealthy weight trajectories during adolescence in boys. Detrimental effects of exposure to a domestic violence environment may take root in the first few years of development for boys.