Ultraprocessed Foods (UPFs) have become a significant part of modern diets. These are items like frozen pizza, ready-to-eat meals, instant noodles, and many commercially produced breads. They are often characterized by lengthy ingredient lists, artificial additives, and minimal whole food content. Recent research is increasingly highlighting the potential health concerns linked to high consumption of ultraprocessed foods.
A comprehensive review published in the British Medical Journal (BMJ) in 2024 brought considerable attention to this topic. This review, analyzing 45 studies involving nearly 10 million participants, suggests a strong correlation between higher ultraprocessed food intake and an increased risk of mortality from various causes. Furthermore, it linked UPF consumption to 32 distinct health conditions, including cardiovascular disease, mental health disorders, and type 2 diabetes.
These studies, included in the BMJ review, utilized the NOVA classification system. Developed by researchers in Brazil, NOVA categorizes foods into four groups based on their processing level: unprocessed or minimally processed, processed culinary ingredients, processed foods, and ultraprocessed foods. This system helps to standardize the way different foods are classified in nutritional studies.
The NOVA system, established in 2009, has gained recognition from organizations like the World Health Organization (WHO). However, it’s important to note that not all institutions, such as the United States Department of Agriculture (USDA), have universally adopted it. Classifying processed foods remains a complex issue with ongoing discussions among experts in public policy, nutrition, and the food industry.
Dr. Avlin Imaeda, a gastroenterologist at Yale Medicine specializing in the Metabolic Health & Weight Loss Program, frequently discusses ultraprocessed foods with her patients. She defines them as products with “industrial formulations, chemicals, refined oils, fats, starches, and proteins.” These components contribute to extended shelf life and enhanced palatability, making these foods highly appealing and easy to overconsume.
Dr. Imaeda explains, “That makes people eat more of them, and they are more calorie-dense, meaning people are consuming more calories even when they are eating smaller amounts of food.” This caloric density, combined with their addictive palatability, can contribute to weight gain and related health issues.
While Dr. Imaeda acknowledges the findings of the BMJ review are concerning, she also points out that the increased risk percentages for individual health conditions are relatively modest, often in the range of 1.1-fold to 1.5-fold. However, she cautions that even a seemingly small increase can be significant when considering serious conditions like heart attacks. “If you are talking about a serious health problem, such as a heart attack, a 1.5-fold increase is still a lot,” she states.
She also highlights limitations in some of the reviewed studies. Many relied on patient surveys, which can be less accurate than controlled clinical trials where diet is strictly monitored by researchers. These surveys often depend on participants’ recall of their dietary habits, introducing potential for error.
Another critical issue is the widespread consumption of ultraprocessed foods. The review indicates that UPFs constitute a staggering 67% of the total calories consumed by children and teenagers in the United States. This high level of consumption across the population makes it challenging for researchers to establish a clear baseline comparison group of individuals with low UPF intake.
Dr. Imaeda raises further questions about the direct risks of UPFs versus their indirect effects through obesity. “Plus, how many UPFs have a direct risk of these medical conditions versus how many of them are related to obesity? We know that obesity raises your risk of diabetes, cardiovascular disease, and various cancers,” she notes. It remains unclear to what extent the observed health risks are directly caused by UPFs themselves or mediated by obesity, which is often a consequence of high UPF diets.
In conclusion, the growing body of research, including the recent BMJ review, emphasizes the potential health risks associated with ultraprocessed foods. While more research is needed to fully understand the complexities and nuances of these links, the current evidence suggests that reducing the consumption of ultraprocessed foods and focusing on whole, minimally processed foods is a prudent approach for promoting better health outcomes.
