Childhood victims of bullying have nearly double the risk of being overweight at 18 years of age compared to non-bullied children, according to a new study by researchers at King’s College London.
“Bullying is commonly associated with mental health problems, but there is little research examining the physical health of bullied children,” said Dr. Andrea Danese at the Institute of Psychiatry, Psychology & Neuroscience (IoPPN) at King’s College London.
“Our study shows that bullied children are more likely to be overweight as young adults, and that they become overweight independent of their genetic liability and after experiencing victimisation.”
Earlier research by King’s College revealed that children who had been bullied while growing up in the 1960s were more likely to be obese at the age of 45, yet it remained unclear whether these long-term effects were present earlier in life.
For the new study, the researchers investigated whether bullying in a modern context would have similar effects on weight, particularly since bullying takes on different forms today (e.g. cyberbullying) than it did in the 1960s.
The environment children grow up in today has also changed, with unhealthy food more readily available and sedentary lifestyles more common.
The researchers evaluated data from the Environment Risk (E-Risk) Longitudinal Twin Study, which has followed more than 2,000 children in England and Wales in 1994-1995 from birth to age 18. They assessed bullying victimization in primary school and early secondary school by interviewing mothers and children three different times as the children turned seven, 10 and 12 years of age.
When the children were 18 years old, the researchers measured their body mass index (BMI) and waist-hip ratio, an indicator of abdominal fat.
The findings showed that 28 percent of children in the study had been bullied in either primary school or secondary school (defined as transitory bullying), and 13 percent had been bullied at both primary and secondary school (defined as chronic bullying).
Victims of chronic bullying were 1.7 times more likely to be overweight as young adults than non-bullied children (29 percent prevalence compared to 20 percent). Bullied children also had a higher BMI and waist-hip ratio at the age of 18.
These associations were independent of other environmental risk factors (including socioeconomic status, food insecurity in the home, child maltreatment, low IQ and poor mental health). Also, for the first time, the study showed that children who were chronically bullied became overweight independent of their genetic risk of being overweight.
Finally, at the time of victimization, bullied children were not more likely to be overweight than non-bullied children, indicating that overweight children were not simply more likely to fall victim to bullying.
“Although we cannot definitively say that bullying victimization causes individuals to become overweight, ruling out alternative explanations, such as genetic liability, strengthens the likelihood that this is the case,” said researcher Jessie Baldwin, also from the IoPPN at King’s. “If the association is causal, preventing bullying could help to reduce the prevalence of overweight in the population.
“As well as preventing bullying, our findings emphasize the importance of supporting bullied children to prevent them from becoming overweight, which could include interventions aimed at promoting exercise and healthy eating. Our data suggest that such interventions should start early in life.”
The findings are published in the journal Psychosomatic Medicine.
Source: King’s College London