Two out of three very obese children already show early signs of heart disease, new research suggests.
By the age of 12, two-thirds of severely obese children had at least one risk factor for heart disease such as high blood pressure or high blood glucose levels, a study in The Netherlands found.
Researchers analysed data collected between 2005 and 2007 on 500 children aged between two and 18, including information on blood pressure, cholesterol and blood glucose levels. Some 307 of the children were severely obese.
A body mass index (BMI) of 20.5 for a 2-year-old, 31 for a 12-year-old, and 35 for an 18-year-old was classed as severely obese.
Around 67 per cent of the children had at least one risk factor for heart disease, and over half (56%) had high blood pressure. More than half (54%) also had high levels of low density 'bad' cholesterol, while 14 per cent had high blood glucose levels. Just under one per cent of the overweight children already had type 2 diabetes.
Nearly two thirds (62%) of the under-12s had at least one risk factor for heart disease. Only one child's obesity was down to medical rather than lifestyle factors, the authors said.
Nearly one in three severely obese children came from one parent families.
The researchers, from the VU University Medical Centre in Amsterdam, wrote: "The prevalence of impaired fasting glucose in these children is worrying, considering the increasing prevalence worldwide of type 2 diabetes in children and adolescents.
"Likewise, the high prevalence of hypertension and abnormal lipids may lead to cardiovascular disease in young adulthood."
Doireann Maddock, a senior cardiac nurse with the British Heart Foundation, said: "Although it was a small study, the findings leave a bad taste in the mouth.
"It's a huge concern so many obese children were identified as already having at least one risk factor for heart disease, including high blood pressure, high blood glucose and problems with cholesterol levels.
"However, this is a problem that can be addressed by stopping young people becoming overweight and obese in the first place. Highlighting the importance of healthy eating and physical activity from an early age will help protect the heart health of future generations."
The study findings are published in the journal Archives of Disease in Childhood.