A study that tracked participants found that high consumption of red meat increased their risk of developing type 2 diabetes by 51%.
Increased risk was still present even when other factors, such as BMI, smoking status, and ethnicity, were accounted for.
Researchers at the Harvard T.H. Chan School of Public Health tracked the eating habits of over 280,000 people for more than three decades to see how long-term dietary patterns affected the risk of developing type 2 diabetes.
They found that consuming more than one serving of red meat daily was associated with significantly increased risk. This backs up previous studies that have linked red meat to the risk of developing type 2 diabetes.
The exact causation isn’t entirely clear. Study participants who ate more than one serving of red meat daily also consumed more calories, on average, than those who ate less red meat. Overall, they were also more likely to have other known risk factors for type 2 diabetes, including being less physically active, a current smoker, and less likely to use multivitamins.
However, the study found that an increased risk was still present even when body weight was accounted for. The increased risk from eating more than a single serving of red meat daily was just over 50%. When adjusted to account for risk associated with BMI, the total increased risk was still about 12%. The risk was higher for people with other known risk factors, such as smoking.
It’s been suggested that red meat might have properties that can lead to the development of type 2 diabetes. For instance, red meat has been linked to inflammation and insulin resistance, and the iron found in red meat has been linked to pancreas damage.
The risk can increase with consuming processed red meats with added nitrates. Evidence has shown that nitrates, which are added to help preserve meats, can cause adverse health effects. In addition to being a potential carcinogen, nitrates and their byproducts can promote insulin resistance.
Replacing even one serving per day of red meat with a lean or extra lean protein can potentially reduce the risk of developing type 2 diabetes. Multiple studies suggest that reducing red meat consumption reduces the risk of developing health conditions like heart disease and high blood pressure.
Recruitment for the study began in 1976. Participants were healthcare professionals and included 238,129 female registered nurses between the ages of 25 and 55 and 51,529 male veterinarians, dentists, pharmacists, optometrists, osteopath physicians, and podiatrists between the ages of 40 and 75.
Researchers sent health data collection surveys to participants biennially for up to 36 years. Participants with a baseline history of certain conditions, including diabetes, cancer, and multiple heart conditions, were excluded from the final analysis. Risk factors, such as BMI, smoking status, and ethnicity, were factored into statistical analysis.
The average American diet and its associated health risks
The average American eats about 4.5 servings of red meat every week. A 2022 survey and statistical analysis found that about 20% of Americans’ red meat consumption comes from fast-food restaurants. The link between red meat and high cholesterol, high blood pressure, and other health concerns is well documented. However, red meat is far from the only dietary staple that can put health at risk. 
For instance, the Dietary Guidelines for Americans recommends that less than 10% of daily calories come from saturated fat, but data collection shows that only about one-third of American adults over the age of 20 meet this recommendation.
The American Heart Association recommends no more than 36 grams of added sugar per day for men and 25 grams of added sugar per day for women. The organization reports that the average American adult consumes around 71 grams of added sugar per day. Similarly, guidelines recommend consuming no more than 2,300 milligrams of sodium daily, but the average American consumes about 3,400. Just looking at caloric intake, there’s a large gulf between recommendations and reported averages. According to some reports, the average American consumes more than 3,600 calories each day.
Recent studies have found a potential link between the standard American diet and the risk of developing health issues, including various cancers, mental health conditions, and autoimmune conditions. However, even for those who know and understand the risks, it can be difficult to make changes. Cardiologist Kevin Campbell, MD, suggests advising your patients to start with small, manageable steps.
“I like to tell people to start by stocking up on those healthy snacks—fruits, vegetables— making sure you have all of that in the house,” he says. “And then, if they can, meal planning on the weekends can be a huge help.”