June 7, 2010— -- Children whose mothers reported chronic abuse at the hands of an intimate partner were more likely to be obese at age 5 than those from violence-free families, researchers found.
After controlling for several other factors, including maternal obesity and depression, children whose mothers reported chronic violence had 1.8 times the odds of being obese, according to Dr. Renée Boynton-Jarrett of Boston University and colleagues.
The association appeared to be magnified in girls and in families living an unsafe neighborhood, the researchers reported in the June issue of Archives of Pediatrics and Adolescent Medicine.
"If substantiated, these findings may have implications for obesity prevention and reduction efforts," they wrote. "Therefore, interventions aimed at reducing obesity risk may be enhanced by incorporating strategies to address family violence."
"Moreover," they wrote, "interventions aimed at improving neighborhood safety may have a benefit on reducing childhood obesity risk, even among those exposed to family violence."
It is recognized that family environment plays a role in childhood obesity, although the impact of adverse psychosocial exposures is not well understood, according to Boynton-Jarrett and her colleagues.
Previous studies have linked intimate partner violence in childhood with altered neuroendocrine system profiles, impaired socioemotional development, cognitive functioning, attachment to caregivers and emotional regulation, as well as poorer physical and mental health.
Some researchers have suggested that inactivity and overeating may be ways to cope with abuse that lead to the disruption of metabolic systems and hormonal changes.
To examine the relationship between exposure to domestic violence and obesity in children, Boynton-Jarrett and her colleagues turned to the Fragile Families and Child Well-being Study, a study conducted in 20 large cities in the United States.
The current analysis included 1,595 children born between 1998 and 2000 and their mothers. Intimate partner violence and perception of neighborhood safety were reported by the mothers.
Overall, 16.5 percent of the children were obese at age 5.
About half (49.4 percent) of the mothers reported physical, sexual, or restrictive intimate partner violence at some point, including 16.8 percent who reported chronic abuse.
The likelihood of being obese at age 5 was greater for children whose mothers reported chronic abuse. The odds were higher for girls than for boys.
The researchers said several potential mechanisms may underlie the relationship between exposure to intimate partner violence and obesity in children.
"Family conflict may limit maternal emotional availability for caretaking needs and influence parental feeding style and patterns," they wrote.
"Alternatively," they continued, "family violence is distressing and may cause affective dysregulation, leading to decreased impulse control" -- and, hence, overeating.
One possible biological explanation they offered was that the stress of conflict in the home could affect children's levels of the stress hormone cortisol and other hormones, leading to overeating and a higher tendency to accumulate fat.
In addition, women who are abused may be more likely to live in communities with greater social disorganization, disadvantage, and violence, which could affect children's ability to exercise outdoors and enhance the mothers' social isolation, which would affect their caretaking ability.
The authors listed several limitations of the study, including the reduced sample of participants for whom longtudinal data on body mass index (BMI) were available, the use of self-reported abuse, and the lack of information on several important predictors of obesity, including nutritional content of diet, dietary patterns, degree of breastfeeding, and physical activity.