Most cases of type 2 diabetes can be linked to making poor food choices, a new study finds.
Researchers from Tufts University in Boston linked poor diet to 14 million cases of type 2 diabetes — about 70% of new diagnoses globally — in 2018.
The biggest impact came from insufficient intake of whole grains, too much refined rice and wheat, and overconsumption of processed meat.
"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," said study co-author Dr. Dariush Mozaffarian, a professor of nutrition and dean for policy at Tufts' School of Nutrition Science and Policy.
"These new findings reveal critical areas for national and global focus to improve nutrition and reduce devastating burdens of diabetes," Mozaffarian said in a Tufts news release.
In type 2 diabetes, the body's cells are resistant to insulin, a hormone necessary to convert the food you eat into fuel for the body.
The scientists looked at data from 1990 and 2018, using a research model of dietary intake in 184 countries that was developed at Tufts.
All of the countries studied saw an increase in type 2 diabetes cases during that time frame.
Poor diet is causing a larger proportion of total type 2 diabetes incidence in men versus women, in younger versus older adults and in urban versus rural residents, according to the research.
Other dietary factors, such as drinking too much fruit juice and not eating enough non-starchy vegetables, nuts or seeds, had less of an impact on new cases of the disease.
The investigators found the greatest number of type 2 diabetes cases linked to diet in Central Asia, and Central and Eastern Europe, especially in Poland and Russia where diets are rich in red and processed meats and potatoes.
They also found high numbers in Latin America and the Caribbean, especially in Colombia and Mexico. This was attributed to high consumption of sugary drinks and processed meat, as well as low whole grain intake.
Diet had less impact on type 2 diabetes in South Asia and sub-Saharan Africa. However, researchers saw the largest increases in diabetes due to diet between 1990 and 2018 in sub-Saharan Africa.
India, Nigeria and Ethiopia had the fewest cases of type 2 diabetes related to unhealthy eating among the 30 most populated areas studied.
"Left unchecked and with incidence only projected to rise, type 2 diabetes will continue to impact population health, economic productivity, health care system capacity, and drive heath inequities worldwide," said co-author Meghan O'Hearn, who was a PhD candidate at Tufts during the study and is now with Food Systems for the Future.
"These findings can help inform nutritional priorities for clinicians, policymakers, and private sector actors as they encourage healthier dietary choices that address this global epidemic," O'Hearn said.
The study results were published online April 17 in the journal Nature Medicine. The research was supported by the Bill and Melinda Gates Foundation.