The study emphasizes that reducing and replacing red meats with healthier proteins such as nuts, low-fat dairy and whole grain can significantly lower the risk of Type II diabetes.

The research was led by An Pan research fellow in the HSPH Department of Nutrition, will be published online in the American Journal of Clinical Nutrition

Senior author Frank Hu, professor of nutrition and epidemiology at HSPH, and colleagues analyzed questionnaire responses from combined updated meta-analysis, collecting data from their new study with data from existing studies that included a total of 442,101 participants, 28,228 of whom developed type II diabetes during the study.

After making adjustments to age, body mass index (BMI), and other lifestyle and dietary risk factors, the researchers found that daily 100-gram serving of unprocessed red meat was associated with a 19 percent increased risk of type 2 diabetes. They also found that one daily serving of half that quantity of processed meat 50 grams was associated with a 51 percent increase.

"Clearly, the results from this study have huge public health implications given the rising type 2 diabetes epidemic and increasing consumption of red meats worldwide," said Hu. "The good news is that such troubling risk factors can be offset by swapping red meat for a healthier protein."

The researchers found that individuals who substituted one daily serving of red meat with serving of nuts per day lowered the risk of type II diabetes by 21 percent; substituting low-fat dairy had 17 percent lower risk: substituting whole grains had 23 percent lower risk.

Researchers emphasized that based on their results, consumption of processed red meat like hot dogs, bacon, deli meats should be minimized and unprocessed red meats should be reduced. If possible, they add, red meat should be replaced with healthier choices, such as nuts, whole grains, low-fat dairy products, fish, or beans.

This new study finds that both unprocessed and processed meats pose a type 2 diabetes risk, thus helping to clarify the issue. In addition, this study is among the first to estimate the risk reduction associated with substituting healthier protein choices for red meat.

Researchers suggested the U.S. dietary guidelines should distinguish red meat from healthier protein sources.