Air pollution, smoking and high population density could be contributing factors to obesity among children, researchers have said.
In the last 45 years, obesity rates have tripled so a global team wanted to investigate how combined environmental factors might impact the health condition, commonly associated with type 2 diabetes.
The study involved more than 1,300 children aged between six and 11 took from the UK, France, Greece, Lithuania and Spain.
The researchers analysed more than 170 factors that children are exposed to in pregnancy or childhood.
Each child had their body mass index (BMI), waist circumference and skinfold thickness measured. Blood and urine samples were also taken from the young people, as well as from their mothers during their pregnancy.
The research team discovered that exposure to both second-hand smoking and maternal smoking during pregnancy increased the chance of obesity. Air pollution was also a risk factor, as well as living in a built-up environment.
One of the study authors, Leda Chatzi who is Professor of Preventive Medicine at the University of Southern California, added: “The children who live in densely populated areas and go to schools in areas with few services and facilities were more likely to be obese.”
Lead researcher Martine Vrijheid, Research Professor at the Global Health Institute (ISGlobal) in Barcelona, said: “The prevalence of childhood obesity is increasing at alarming rates across the globe and may have increased even more than usual during the COVID-19 lockdown period.
“These findings provide further evidence that modifying environmental exposures early in life can limit the risk of obesity and associated complications. The implications for public health are important since these results may help to identify obesity-related exposures that could be targeted for prevention and intervention early in life.”
The study findings have been published in the Environmental Health Perspectives journal.