July 19, 2025, 5:44 am | Read time: 6 minutes

Processed meat products have long been suspected of promoting chronic diseases. However, the strength of the connection–and whether even small amounts are harmful–remained unclear until now.

A research team led by Demewoz Haile from the Institute for Health Metrics and Evaluation (IHME) at the University of Washington aimed to find out exactly that. The goal was to systematically quantify the impact of common food groups on the development of chronic diseases. Given that chronic diseases like diabetes, coronary heart disease (CHD), and colon cancer cause a significant disease burden worldwide, precise insights into diet-related risk factors are of great importance for public health.¹

How the Researchers Proceeded

The study was conducted as a so-called “Burden of Proof” analysis–an advanced method based on systematic reviews (meta-analyses) and statistical modeling. The unique aspect: With this special method, the researchers were able to calculate dose-response relationships–that is, how much the risk increases with different consumption levels. They deliberately calculated conservatively to avoid overestimating effects. They used only existing data from large observational studies.

What is the “Burden of Proof” Method?

The “Burden of Proof” studies are a series of particularly elaborate meta-analyses developed by the IHME. They compile data from numerous observational studies and assess how strong and reliable the connection is between a risk factor (e.g., processed meat) and a disease (e.g., type 2 diabetes). The result is presented with a star system–from weak (one star) to strong evidence (five stars). The aim is to reduce scientific uncertainties and enable reliable statements for dietary recommendations.

For the present study, data from a variety of prospective cohort studies and case-control studies were included, such as:

• 15 studies with over 1.1 million participants on the link between processed meat and type 2 diabetes
• 11 studies with over 1.17 million participants on processed meat and CHD
• 18 studies with over 2.67 million participants on processed meat and colon cancer

Also interesting: The less meat in the diet, the lower …

Even One Sausage a Day Is Too Much

The analysis showed that even the smallest daily amounts of processed meat are associated with a measurable increase in disease risk–in all areas studied.

The risk of developing type 2 diabetes increased by an average of 11 percent with a daily intake of 0.6 to 57 grams. Assuming a person eats 50 grams per day (equivalent to two to three slices of cold cuts or a Vienna sausage), the risk increased by a whopping 30 percent. The results for colon cancer were similarly unfavorable. Here, a daily intake of 0.78 to 55 grams resulted in an average risk increase of seven percent. Those who eat 50 grams of processed meat daily have a 26 percent higher risk of colon cancer. For CHD, a daily 50-gram portion led to a 15 percent increase in risk.

The study authors noted: The risk increased continuously with the amount–but particularly strongly at low, everyday amounts.

Sugary Drinks and Trans Fats Also Showed a Negative Effect

The authors also considered two other common food groups that showed a negative effect on the development of chronic diseases: sugary drinks and trans fats. The analysis included

• 19 studies on sugar-sweetened beverages and diabetes (563,444 participants), eight studies on CHD (961,176 participants), and
• 6 studies with 226,509 people on trans fats and CHD.

The result: Consuming sugar-sweetened beverages (e.g., soft drinks) increased the risk of diabetes by 20 percent and CHD by seven percent when 250 grams were consumed daily. If trans fats (e.g., in croissants, fries, ready meals) made up one percent of daily energy intake, the risk of chronic diseases increased by 11 percent.

Significance of the Results

Even the smallest amounts of sausage, soft drinks, and trans fats can increase the risk of three of the most common chronic diseases worldwide. Particularly critical: The steepest increase in risk occurred with low daily intake–in areas that many people regularly consume. For everyday life, this means: Even those who “moderately” indulge in processed meat or soft drinks may potentially expose themselves to an increased risk of disease. This result is also reflected in the 2024 updated recommendations of the German Nutrition Society. Instead of 600 grams, only 300 grams of meat and sausage can be consumed per week–if one wants to eat these foods at all. The DGE emphasizes: “Even with a consumption of none or less than 300 grams of meat per week, the nutritional goals can be achieved.”²

For research, the study underscores the need to precisely capture dose-response relationships–not least to be able to provide realistic and effective dietary recommendations.

Context and Possible Limitations

The study uses an advanced methodology with systematic literature search and precise dose-response modeling. The “Burden of Proof” method is among the most demanding approaches in nutritional epidemiology today. Also noteworthy is the transparency of the work: The data, methods, and codes are publicly accessible, and conflicts of interest have been disclosed and excluded. The work was peer-reviewed and published in “Nature Medicine,” a renowned journal.

However, there are limitations: The results are based on observational studies–studies that cannot prove cause-and-effect relationships but only show associations. These were each internally rated with only two stars, “indicating weak associations or conflicting evidence and underscoring both the need for further research and–given the high burden of these chronic diseases–the advisability of continuing to limit the consumption of these foods,” the study authors conclude.

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Less Is More

Small amounts of processed meat seem harmless, but they are not. The current study shows that small amounts of sausage and the like are enough to significantly increase the risk of chronic diseases such as diabetes, CHD, and colon cancer. Particularly insidious: The greatest risk increase occurs with small, everyday portions. So, if you want to do something good for your health in the long term, you might want to opt for the plant-based alternative at your next snack. Less is clearly more in this case–and sometimes even life-extending.