People who eat just two servings of red meat per week may have an increased risk of developing diabetes compared to people who eat fewer servings, and the risk increases with greater consumption, according to a new study.

The study, led by researchers from Harvard University’s T.H. Chan School of Public Health, also found that replacing red meat with healthy plant-based protein sources, such as nuts and legumes, or modest amounts of dairy foods, was associated with reduced risk of type 2 diabetes.

“Our findings strongly support dietary guidelines that recommend limiting the consumption of red meat, and this applies to both processed and unprocessed red meat,” said first author Xiao Gu, a postdoctoral research fellow in the Department of Nutrition at Harvard.

For the study, published in The American Journal of Clinical Nutrition, the researchers analysed health data from 216,695 participants from the Nurses’ Health Study (NHS), NHS II, and Health Professionals Follow-up Study (HPFS).

Diet was assessed with food frequency questionnaires every two to four years, for up to 36 years. During this time, more than 22,000 participants developed type 2 diabetes.

The researchers found that consumption of red meat, including processed and unprocessed red meat, was strongly associated with increased risk of type 2 diabetes.

Participants who ate the most red meat had a 62 per cent higher risk of developing diabetes compared to those who ate the least.

Every additional daily serving of processed red meat was associated with a 46 per cent greater risk of developing diabetes and every additional daily serving of unprocessed red meat was associated with a 24 per cent greater risk.

The researchers also estimated the potential effects of substituting one daily serving of red meat for another protein source.

They found that substituting a serving of nuts and legumes was associated with a 30 per cent lower risk of type 2 diabetes, and substituting a serving of dairy products was associated with a 22 per cent lower risk.

“Given our findings and previous work by others, a limit of about one serving per week of red meat would be reasonable for people wishing to optimise their health and wellbeing,” said senior author Walter Willett, professor of epidemiology and nutrition.