London: Children who are bullied in primary and secondary school are nearly twice as likely to be overweight at the age of 18 than non-bullied children, according to a new study by researchers from King’s College London. Previous research by the team at King’s has shown that children who experienced bullying while growing up in the 1960s were more likely to be obese at the age of 45, yet it was unclear whether these long-term effects were present earlier in life.
In this new study, published in Psychosomatic Medicine,
the researchers set out to examine whether bullying in a modern context
would have similar effects on weight, given that it may take 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 analysed 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 victimisation in primary school and early secondary school
through interviews with mothers and children at repeated assessments at
the ages of 7, 10 and 12.
When the children were aged 18, the researchers measured their body
mass index (BMI) and waist-hip ratio, an indicator of abdominal fat.
They found that 28 per cent of children in the study had been bullied
in either primary school or secondary school (defined as transitory
bullying), and 13 per cent had been bullied at both primary and
secondary school (defined as chronic bullying).
Children who were chronically bullied in school were 1.7 times more
likely to be overweight as young adults than non-bullied children (29
per cent prevalence compared to 20 per cent). 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). In addition, and
for the first time, analyses showed that children who were chronically
bullied became overweight independent of their genetic risk of being
overweight. Finally, at the time of victimisation, 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
Dr Andrea Danese
from the Institute of Psychiatry, Psychology & Neuroscience (IoPPN)
at King’s College London, said: ‘Bullying is commonly associated with
mental health problems, but there is little research examining the
physical health of bullied children. 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
also from the IoPPN at King’s, said: ‘Although we cannot definitively
say that bullying victimisation causes individuals to become overweight,
ruling out alternative explanations, such as genetic liability,
strengthens the likelihood that this is the case. 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 emphasise 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.’