Ultra-processed foods found to drive inflammation and obesity

Walk into any grocery store in Canada and you’ll find aisles stacked high with brightly packaged snacks, frozen meals, sugary cereals, and ready-to-eat foods that promise convenience. These are known as ultra-processed foods, and they are no small part of the Canadian diet. In fact, researchers report they now make up nearly half of what Canadians eat each day. While quick and easy to prepare, new evidence suggests these products are taking a serious toll on health.

A team at McMaster University has just completed the first large-scale Canadian study to examine the relationship between ultra-processed food intake and risk factors for major chronic diseases. The results, published in the journal Nutrition and Metabolism, are raising alarms among health experts and may shape future food policies.

More than 6,000 Canadian adults took part in the study, representing a wide mix of ages, lifestyles, and income levels. Participants filled out detailed questionnaires as part of the Canadian Health Measures Survey, run by Health Canada and Statistics Canada. They were also given in-person assessments at mobile clinics where their weight, waist size, blood pressure, cholesterol, insulin, and other biomarkers were measured.

When researchers analyzed the data, they saw a clear pattern. People who ate the most ultra-processed foods showed worse health outcomes. They had higher body mass index, larger waist circumference, and higher blood pressure compared to lighter consumers. Blood tests showed higher triglycerides and insulin, with lower levels of protective HDL cholesterol.

The study linked these foods to much more than weight gain. Many associations stayed significant even after adjusting for BMI. This means ultra-processed foods may harm the body through other pathways, including inflammation and insulin resistance. These harmful processes disrupt metabolic regulation and strongly drive cardiovascular disease and type 2 diabetes.

One of the most striking findings involved inflammatory biomarkers. Researchers found that participants who consumed large amounts of ultra-processed foods had higher levels of C-reactive protein, or CRP, a substance released by the liver when inflammation is present. They also had higher counts of white blood cells, which rise when the body perceives a threat.

“These two biomarkers indicate that these foods are causing an inflammatory response in our bodies,” says Anthea Christoforou, an assistant professor in the Department of Kinesiology at McMaster University and senior author of the study. “In a sense, this suggests that our bodies are seeing these as non-foods, as some kind of other element.”

Inflammation has long been linked to chronic illness. When it persists, it can damage blood vessels, interfere with insulin function, and strain the heart. For researchers, the discovery that diet alone can spark this response underscores just how harmful these products can be.

Not all Canadians consume the same amount of ultra-processed foods. The study found that the biggest consumers were more likely to be men, have lower income and education levels, and eat fewer fruits and vegetables. On average, Canadians ate more than three servings of these foods per day. Those in the top group reported six servings daily—about double the amount.

The heavy marketing, low cost, and sheer convenience of these foods may explain their dominance, especially among people with less time or money to spend on fresh produce or homemade meals. Yet the health effects were not confined to any one group.

“Ultra-processed foods are impacting health across all socioeconomic groups,” says Angelina Baric, a graduate student in the Department of Kinesiology at McMaster and co-author of the study. “While some populations are more exposed to these foods, our findings show that the health risks persist independently of income and education. This highlights the need for broad, equitable food policies that protect everyone.”

Ultra-processed foods are not just about sugar, salt, or fat. They are manufactured products containing additives, preservatives, flavorings, and emulsifiers. Many are designed to be hyper-palatable, making them difficult to resist. “We have this very complex food supply that is more than just the nutritional composition of a food,” explains Christoforou. “It may be about the additives. The way the food is prepared. It's related to the packaging and the marketing of that food. All these things come together to create this food environment that really affects the healthfulness of our diets.”

In other words, these foods may be harming people in ways not fully captured by traditional nutrition labels. The combination of chemical additives, industrial processing, and aggressive advertising creates a cycle where consumption becomes normalized and even encouraged.

The findings in Canada mirror results from studies in other countries, including Brazil, the United States, and several European nations. Globally, ultra-processed foods have been shown to increase risks of obesity, heart disease, cancer, and premature death. As middle- and high-income countries shift further toward packaged convenience products, health disparities also widen. In Canada, this study makes clear that the risks are not just hypothetical—they are already showing up in the blood work of thousands of adults.

Health Canada has already issued guidelines urging citizens to reduce their intake of processed foods. But the new evidence may push policymakers to take stronger action, such as introducing clearer labeling, restricting marketing to children, or providing incentives for healthier food options in low-income areas.

Baric believes the data provide a crucial early warning. “We found consistent evidence that eating ultra-processed foods is associated with cardiometabolic risk factors, which not only reinforces the evidence we have seen linking these foods with rising overweight and obesity rates in Canada and other parts of the world, but also provides more detailed information about what’s happening in the body before a full disease,” she says.

The McMaster team is already planning further investigations. Future studies will explore how processed food intake affects children’s diets, as well as women’s health outcomes in areas like fertility, menstruation, and menopause. Researchers are also digging deeper into the biological mechanisms, aiming to identify exactly how additives and preparation methods may trigger inflammation and metabolic disruption.

The take-home message from this research is simple: the more ultra-processed foods in your diet, the greater the risk to your heart and metabolism. While convenience and affordability are real concerns, the long-term costs to health may far outweigh the short-term benefits.

Reducing intake doesn’t necessarily mean eliminating all packaged foods, but cutting back where possible—replacing sugary cereals with oatmeal, choosing fresh fruit over packaged desserts, or preparing simple homemade meals instead of relying on frozen entrees—can make a significant difference.

The evidence now leaves little doubt. Ultra-processed foods are more than just “junk food.” They are engineered products that can set off biological changes linked to some of the most serious health problems Canadians face today.

Note: The article above provided above by The Brighter Side of News.

Like these kind of feel good stories? Get The Brighter Side of News' newsletter.