A 2024 report by The BMJ review included 45 distinct studies involving more than 9.8 million participants. The multitude of adverse health outcomes revealed by the review can be broadly classified into the following seven categories:

  1. Mortality: All-cause mortality, cancer-related mortality, cardiovascular disease-related mortality, and heart disease-related mortality
  2. Cancer: Overall cancer, breast cancer, colorectal cancer, central nervous system tumors, chronic lymphocytic leukemia, pancreatic cancer, and prostate cancer
  3. Mental health: Poor sleep, anxiety, common mental disorders, and depression
  4. Cardiovascular health: Cardiovascular disease, hypertension, hypertriglyceridemia, and low HDL cholesterol levels
  5. Respiratory health: Asthma and wheezing
  6. Gastrointestinal health: Crohn’s disease and ulcerative colitis
  7. Metabolic health: Abdominal obesity, high blood sugar, metabolic syndrome, nonalcoholic fatty liver disease, obesity, and Type 2 diabetes

The researchers assessed the credibility and quality of evidence from various studies and found that excessive consumption of ultra-processed foods was particularly associated with a higher risk of cardiometabolic issues, common mental disorders, and mortality outcomes.

According to the research, there is “compelling evidence” linking higher intake of these foods with significant health issues:
  • Cardiovascular Health: A 50% increased risk of mortality related to cardiovascular diseases.
  • Mental Health: An increase of 48-53% in the risk of anxiety and common mental disorders.
  • Diabetes: A 12% higher risk of developing Type 2 diabetes.
Moreover, the study presents highly suggestive evidence that:
  • Overall Mortality: Consuming more ultra-processed foods correlates with a 21% increased risk of death from any cause.
  • Depression: A 22% higher risk of depression.
  • Disease Specific Risks: An increase from 40% to 66% in the risk of mortality from heart disease, along with higher risks for Type 2 diabetes, obesity, and sleep disturbances.
Dr. Zheng, one of the researchers, points out that the link between ultra-processed foods and diabetes is particularly robust, backed by high-quality research. He explains that diabetes can compromise vascular and immune functions, thereby elevating the risk for numerous other health conditions in individuals already at risk for diabetes.
The BMJ (formerly known as The British Medical Journal) does note that most of the evidence cited in the studies is observational, meaning that the associations between ultra-processed food intake and health outcomes like cardiovascular disease, mental health disorders, diabetes, and overall mortality are correlations.  While the studies do not establish direct causation due to their observational nature, some researchers argue that there is “compelling” or “highly suggestive” evidence which might lean towards causality. The bottom line: junk food is called ‘junk’ food for a reason.