suggested that obesity in children as young as five may be having a significant effect on the health of their hearts.
The study found that children and adolescents who are obese already have several high risk factors for heart disease, including raised blood pressure, cholesterol and sugar levels, and a thickening of the heart muscle- all of which can increase their chances of having a stroke or contracting heart disease by 40 per cent.
Experts have labeled the findings “astounding” and far more dramatic than had previously been expected.
“We wanted to look at the relationship between the body mass index of school-age children and the known risk factors for heart disease and stroke,” said Claire Friedemann, first author on the study and a DPhil student in the Department of Primary Care Health Sciences at Oxford University
The size of the link between body mass index (BMI) and risk factors like blood pressure, cholesterol and regulation of blood sugar levels had not been fully established before in children aged 5-16.
BMI is a calculation of weight divided by height squared, with a figure of 17 or less classified as underweight; a value between 17-25 as normal; over 25 as overweight; and over 30 as obese.
The team analysed the results of more than 63 studies involving 49,220 healthy children aged between five and 15 years old.
Although the studies included in the analysis do not show what happens when the children become adults, evidence available from other studies indicates that the same patterns continue. As a result, the researchers believe that these elevated risk factors could have a marked effect on the future health of obese children.
Worryingly, official figures show that a third of children aged ten and 11 were either overweight or obese in 2010/11, with this figure continuing to rise.
“If a child is overweight it could have wider consequences for their health that they may not be able to just grow out of, and so taking action early is important,” said Claire Friedemann.
She added: “Healthy habits are much easier to begin as a child and then maintain into adulthood.
Dr Carl Heneghan of the University of Oxford and a co-author on the paper, said: “The relationship between obesity in children and cardiovascular risk factors such as blood pressure was much greater than we anticipated.
“The magnitude of the effect of obesity upon increasing cardiovascular risk in children is deeply worrying in terms of their future risks of heart disease.”
Dr Matthew Thompson, reader in primary health care at the University of Oxford, said: “Being overweight as a child is more than just about appearance – many children’s hearts and blood vessels are already getting damaged when they are overweight or obese.
“Knowing that your heart and blood vessels are already damaged by being overweight or obese might help children and their parents put changes in place to change eating and lifestyle habits.”
The results of this study have been published online by The British Medical Journal.