Long-term Impact of Ultra-Processed Foods on Mental Health

In recent years, health experts have been scrutinizing the impacts of our diet on both our physical and mental well-being.

You probably know that ultra-processed foods aren’t great for your body. Now, a new study shows they’re not good for your mental health either, especially when it comes to the risk of depression over time.

The Study in a Nutshell

Researchers in Australia decided to dig into this subject and published their findings in the Journal of Affective Disorders. The study analyzed data from 23,299 individuals, aged between 27 and 76, who were part of the Melbourne Collaborative Cohort Study. Before the study began, the team excluded individuals who displayed signs of psychological distress.

The study kept tabs on participants for a span of 13 to 17 years. At the end of this period, researchers assessed their emotional well-being using the Kessler Psychological Distress Scale.

The findings were pretty universal. Regardless of your age, gender, or how often you hit the gym, the data showed a clear pattern: If a significant part of your diet was made up of ultra-processed foods, you were more likely to experience symptoms of depression a decade later. This extended timeframe highlights the enduring impact that our food choices can have on our long-term mental health.

Another eye-catching detail is the linear relationship between ultra-processed food and depression risk. Simply put, the more you eat, the higher your risk gets.

In fact, the study’s first author, Dr. Melissa Lane, pointed out that the risk became notably higher when about 30% of a person’s total food intake was ultra-processed.

While the study can’t say for sure if eating these foods causes depression, it does make a strong case for a connection between the two. Researchers even took steps to minimize the chance of people eating processed foods because they were already depressed.

Dr. Lane points out that ultra-processed foods often lack important nutrients like protein and fiber while packing in harmful additives. This could mess with your gut and cause inflammation, which other studies have linked to depression.

The takeaway? Although we can’t say it’s a definite cause-and-effect relationship, there’s growing evidence that your food choices could significantly affect your mental health.

What Are Ultra-Processed Foods?

Before we dig further, let’s clarify what we mean by ultra-processed foods. These items have gone through a lot of tinkering and usually feature a long list of ingredients. They’re built for flavor and staying fresh on the shelf, but they often miss out on essential nutrients your body needs. So, what falls under this category?

Ultra-Processed Foods Linked to Higher Depression Risk New Research

Here’s a quick list:

  • Sugary sodas
  • Frozen pizzas
  • Instant noodles
  • Breakfast cereals high in sugar
  • Pre-packaged cookies and cakes
  • Processed meats like hot dogs and sausages
  • Chips and other salty snacks
  • Fast-food burgers

What Can You Do?

Even though we can’t change our past eating habits, there’s a silver lining. Moving away from a diet high in ultra-processed foods might be a good idea if you’re looking to improve your mental health.

To sum it up, what you eat might be affecting more than just your waistline; it could be impacting your mental health too. This study isn’t the final say, but it joins a growing list of research that tells us our diet really matters for our overall well-being.


Lane, M.M., Lotfaliany, M., Machado, P., Jacka, F.N., Mohebbi, M., O’Neil, A., Werneck, A.O., Monteiro, C., Loughman, A., Rocks, T., Travica, N., Berk, M., Opie, R.S., & Marx, W. (2023). Change in Ultra-Processed Food Consumption Moderates Clinical Trial Outcomes in Depression: A Secondary Analysis of the SMILES Randomised Controlled Trial. Preprints. https://doi.org/10.20944/preprints202308.1110.v1




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