The International Diabetes Federation predicts the number of diabetes cases will double by the year 2030, according to the latest statistics.
A report released on Monday reveals that more than 552 million people could have diabetes, which is roughly one out of every 10 adults.
The group bases the report on aging and demographic changes.
"It's a credible figure," said Gojka Roglic, head of World Health Organization's diabetes unit. "But whether or not it's correct, we can't say."
There are currently 346 million people worldwide with diabetes, which is averaged to one out of every 13 adults, according to the WHO.
Roglic attributed the projected future rise in diabetes cases to aging rather than the obesity epidemic. Most cases of diabetes are Type 2, the kind that mainly hits people in middle age and is linked to weight gain and a sedentary lifestyle.
Roglic said a substantial number of future diabetes cases were preventable.
"It's worrying because these people will have an illness which is serious, debilitating, and shortens their lives," she said. "But it doesn't have to happen if we take the right interventions."