Most cases of type 2 diabetes are caused by poor diet, with meat and bread – your barbecue basics – most at fault.
This is the main finding of an investigation into what people were eating in 184 countries, and how many of them ended up with type 2 diabetes.
The study used a research model developed by the Friedman School of Nutrition Science and Policy at Tufts University.
Overall, the researchers estimate that in 2018, poor or a “sub-optimal” diet contributed to over 14.1 million cases of type 2 diabetes. This accounted for more than 70 per cent of new diagnoses globally.
Dietary factors
In their modelling, the researchers looked at 11 dietary factors. The findings provide a quick and easy guide to what foods we need more of (to avoid type 2 diabetes) and those we need to cut back on. Here are the top offenders:
- The leading factor was not eating enough whole grains, such as red, brown and black rice, oats, barley, quinoa and millet.
- The second leading factor was eating too much refined grains, such as white rice and white flour, where the fibre has been removed. Barbecue bread rolls are a good example.
- Eating too much processed meats such as bacon, salami and sausages.
- Eating too much unprocessed red meat such as chops and steaks.
- Eating too little yoghurt. This is an interesting one, as it elevates the need for the good gut-protecting bacterias found in yoghurt.
- Sugar-sweetened beverages. Perhaps the only surprise here was that sugary drinks weren’t higher in the list.
Drinking too much fruit juice and not eating enough non-starchy vegetables, nuts, or seeds, had less impact on new cases of the disease.
“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 senior author Dariush Mozaffarian, a professor of nutrition and dean for policy at the Friedman School.
“These new findings reveal critical areas for national and global focus to improve nutrition and reduce devastating burdens of diabetes.”
Other findings
People more likely to get type 2 diabetes because of their poor diet are:
- Men more than women. This maybe because men tend to eat more red and processed meat than women.
- Younger adults more than older people. This is interesting given the growing number of bowel cancer cases in young people.
- Urban residents more than 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.
Incidence was also high in Latin America and the Caribbean, especially in Colombia and Mexico, which was credited to high consumption of sugary drinks, processed meat, and low intake of whole grains.
“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,” says first author Meghan O’Hearn, a doctoral student at Friedman.
Other causes of type 2 diabetes
Aside from a sub-optimal diet, risk factors for developing type 2 diabetes include a family history of type 2 diabetes; being overweight or obese, especially with excess weight around the waist; a low level of physical activity; and being over 55 years of age.
For women: Having had gestational diabetes; having polycystic ovarian syndrome; and having a baby that weighed more than 4.5 kilograms.
Aboriginal and Torres Strait Islander people, and people with Pacific Islander, Southern European or Asian backgrounds are more likely to develop type 2 diabetes.
The Friedman researchers note that other recent studies have estimated that 40 per cent of type 2 diabetes cases globally are attributed to sub-optimal diet, lower than their findings.
The research team attributes this “to the new information in their analysis, such as the first ever inclusion of refined grains, which was one of the top contributors to diabetes burdens”.
They also used updated data on dietary habits based on national individual-level dietary surveys, rather than agricultural estimates.
Of the 184 countries included in the Nature Medicine study, all saw an increase in type 2 diabetes cases between 1990 and 2018, representing a growing burden on individuals, families, and healthcare systems.
