Child Abuse Increases Risk of Adult Obesity

A new study suggests that children who suffer maltreatment are up to 36 percent more likely to be obese in adulthood compared to non-maltreated children.

Researchers analyzed data from 190,285 individuals from 41 studies worldwide. Severe childhood maltreatment-including physical, sexual or emotional abuse or neglect-affects approximately 1 in 5 children under 18 in the United Kingdom. In addition to the long-term mental health consequences of maltreatment, there is increasing evidence that child maltreatment may affect physical health.

According to Dr. Andrea Danese, a child and adolescent psychiatrist from King's College London's Institute of Psychiatry and lead author of the study, she believes this has a significant impact on their health later in life.

"We found that being maltreated as a child significantly increased the risk of obesity in adult life," she said, according to a press release. "Prevention of child maltreatment remains paramount and our findings highlight the serious long-term health effects of these experiences."

In their meta-analysis, the authors were able to rule out specific factors which might explain the link - they found that childhood maltreatment was associated with adult obesity independently of the measures or definitions used for maltreatment or obesity, childhood or adult socio-economic status, current smoking, alcohol intake, or physical activity. Additionally, childhood maltreatment was not linked to obesity in children and adolescents, making it unlikely that the link was explained by reverse causality.

However, the analysis showed that after taking depression into account, the link between childhood maltreatment and adult obesity was no longer signiciant. This seems to suggests that depression might help explain why some abused individuals become obese. 

Previous studies also show connections to this theory. Maltreated individuals may eat more because of the effects of early life stress on area of the developing brain linked to inhibition of feeding, or on hormones regulating appetite. On the other hand, maltreated individuals may burn fewer calories because of the effects of early life stress on the immune system leading to fatigue and reduced activity. The authors add that these hypotheses will need to be directly tested in future studies.

"If the association is causal as suggested by animal studies, childhood maltreatment could be seen as a potentially modifiable risk factor for obesity - a health concern affecting one third of the population and often resistant to interventions," Danese said.  "Additional research is needed to clarify if and how the effects of child maltreatment on obesity could be alleviated through interventions after maltreatment has occurred. Our next step will be to explore the mechanisms behind this link."

The findings for the study can be found this week in Molecular Psychiatry.