Researchers have identified three dietary factors that could be most to blame for the increase in type 2 diabetes.
The findings are based on a research model of dietary intake in 184 countries, by researchers at the Friedman School of Nutrition Science and Policy at Tufts University in America.
They considered 11 dietary factors and found the three most responsible for the rise in diabetes were: not eating enough whole grains like oats and whole wheat, eating too much refined rice and wheat, and eating too much processed meat.
The study found that other factors such as drinking too much fruit juice and not eating enough non-starchy vegetables, nuts and seeds had less of an impact on the number of new cases.
Senior author Dariush Mozaffarian, who is Jean Mayer professor of nutrition and dean for policy at the Friedman School, said: "Our study suggests poor carbohydrate quality is a leading driver of diet-attributable type 2 diabetes globally, and with important variation by nation and over time.
"These new findings reveal critical areas for national and global focus to improve nutrition and reduce devastating burdens of diabetes."
The Nature Medicine study found that poor diet contributed to more than 14.1 million cases of type 2 diabetes in 2018 - more than 70% of new cases worldwide.
All 184 countries saw an increase in the disease between 1990 and 2018, with the study also finding that poor diet is causing a larger number of type 2 diabetes cases in men versus women, in younger versus older adults, and in urban versus rural residents.
Central and Eastern Europe and Central Asia, particularly in Poland and Russia, where diets tend to be rich in red meat, processed meat, and potatoes, had the greatest number of type 2 diabetes cases linked to diet.
There was also a high incidence in Latin America and the Caribbean - particularly in Colombia and Mexico - blamed on high consumption of sugary drinks, processed meat, and low intake of whole grains.
Last week, it was revealed that the number of diabetes cases in the UK had passed five million for the first time, with Diabetes UK saying the nation is in a "rapidly-escalating diabetes crisis".
It said the risk factors of type 2 diabetes are "multiple and complex" and include age, family history, ethnicity, as well as being overweight or obese.