The study led by Providence Health Care found that the majority of young people under 30 with diabetes have Type 2 diabetes, which, unlike Type 1, is caused mostly by obesity and physical inactivity and was previously linked to older adults.
Dr. Calvin Ke, one of the study authors, said urgent action is needed to prevent Type 2 diabetes among youth who are being diagnosed as early as age 20, though screening for the disease doesn't start until age 40.
"It used to be assumed that Type 1 diabetes was happening in children and Type 2 diabetes was happening in adults because Type 1 is the genetic type that develops very early in childhood. That is truly no longer the case."
The study released Wednesday and published in the Diabetic Medicine journal, said 62 per cent of white youth with diabetes have Type 2, while in South Asians that number rises to 86 per cent and in Chinese youth it is 87 per cent.
"The Chinese and South Asian populations in this age group have not had their rates measured in a population-wide study as big as this," said Ke, a resident in internal medicine at St. Paul's Hospital in Vancouver.
Studies in the United States have included a huge category of Asians and Pacific Islanders while smaller studies in the United Kingdom don't have nearly the number of participants as the British Columbia research, Ke said.
Previous studies have suggested that 45 per cent of new diabetes cases among adolescents involve Type 2 diabetes, compared to three per cent 20 years ago, but the new study goes even beyond that to say most youth have the preventable form of the disease, he said.
He said eating large quantities of rice, which is high in sugar, has led to a rapid increase in Type 2 diabetes for Chinese youth.
However, a high-calorie North American diet and lack of exercise has exacerbated the condition, he said.
"What's really interesting right now is that there are new numbers coming from China, suggesting that the urbanization there is contributing to a higher level of diabetes. So this is not only happening in Canada, but with globalization we are seeing these changes all over the world."
Senior author Dr. Nadia Khan said although the study did not look at the causes of rising rates of youth diabetes, obesity, high-calorie diets laden with sugar and sedentary lifestyles are likely responsible.
Researchers are concerned that Type 2 diabetes is a growing health problem because it doubles the risk of heart disease, kidney disease, and is a significant risk for early death.