Gobbling up too many refined wheat and rice products, along with eating too few whole grains, is fueling the growth of new cases of type 2 diabetes worldwide, according to a new study that models data through 2018.

"Our study suggests poor carbohydrate quality is a leading driver of diet-attributable type 2 diabetes globally," says senior author Dr. Dariush Mozaffarian, a professor of nutrition at Tufts University and professor of medicine at Tufts School of Medicine in Boston, in a statement.

Another key factor: People are eating far too much red and processed meats, such as bacon, sausage, salami and the like, the study said. Those three factors - eating too few whole grains and too many processed grains and meats - were the primary drivers of over 14 million new cases of type 2 diabetes in 2018, according to the study, which was published Monday in the journal Nature Medicine.

In fact, the study estimated 7 out of 10 cases of type 2 diabetes worldwide in 2018 were linked to poor food choices.

"These new findings reveal critical areas for national and global focus to improve nutrition and reduce devastating burdens of diabetes," said Mozaffarian, who is also the editor in chief of the Tufts Health & Nutrition Letter.

Too many processed foods

Mozaffarian and his team developed a research model of dietary intake between 1990 and 2018 and applied it to 184 countries. Compared with 1990, there were 8.6 million more cases of type 2 diabetes due to poor diet in 2018, the study found.

Researchers found eating too many unhealthy foods was more of a driver of type 2 diabetes on a global level than a lack of eating wholesome foods, especially for men compared with women, younger compared to older adults, and in urban versus rural residents.

Over 60% of the total global diet-attributable cases of the disease were due to excess intake of just six harmful dietary habits: eating too much refined rice, wheat and potatoes; too many processed and unprocessed red meats; and drinking too many sugar-sweetened beverages and fruit juice.

Inadequate intake of five protective dietary factors - fruits, nonstarchy vegetables, nuts, seeds, whole grains and yogurt - was responsible for just over 39% of the new cases.

People in Poland and Russia, where diets tend to focus on potatoes and red and processed meat, and other countries in Eastern and Central Europe as well as Central Asia, had the highest percentage of new type 2 diabetes cases linked to diet.

Colombia, Mexico and other countries in Latin America and the Caribbean also had high numbers of new cases, which researchers said could be due to a reliance on sugary drinks and processed meat, as well as a low intake of whole grains.

"Our modeling approach does not prove causation, and our findings should be considered as estimates of risk," the authors wrote.