Children with obesity face four times the risk of developing Type-2 diabetes later, compared to children with a body mass index (BMI) in the normal range, warns a new study.

For the study, published in the Journal of the Endocrine Society, the researchers examined BMI measurements, diabetes diagnosis records, and other data for 369,362 children between the ages of 2 and 15. They found that 654 children and teenagers were diagnosed with Type-2 diabetes between 1994 and 2013.

Children with higher BMI were found to have far greater risk of developing Type-2 diabetes than those with normal weight. "A child with obesity faces a four-fold greater risk of being diagnosed with diabetes by the age of 25, than their counterpart who is of normal weight," said lead author of the study Ali Abbasi from King's College London. In addition, the researchers found that the rate of children developing Type-2 diabetes increased from an average of six new cases per 100,000 children each year between 1994 and 1998, to an average of 33 new cases per 100,000 children each year, between 2009 and 2013.

"As the prevalence of obesity and being overweight has rapidly risen, an increasing number of children and young adults have been diagnosed with diabetes in the United Kingdom since the early 1990s," Abbasi said.

Researchers also found that 1,318 children were diagnosed with Type-1 diabetes during the same period. As expected, they found no association between obesity and the incidence of type 1 diabetes, which is linked to an underlying autoimmune disorder. Criteria to determine obesity in this study was dependent on the child's age - obesity was classified as having a BMI in the top five per cent of the population for their age, as measured by a 1990 study of British children.