Eating Less Of These Foods May Help With Depression Symptoms

We've all heard that what we eat can influence how we feel. Maybe you've noticed that a balanced breakfast helps you stay focused through the morning, or that skipping lunch leaves you feeling irritable by midafternoon.

But when it comes to mental health, the relationship between food and mood gets a little more complicated.

Researchers have spent years investigating how dietary patterns influence depression, anxiety, and overall emotional well-being. While research has repeatedly linked higher ultra-processed food intake to depression and anxiety, there's still a lot we don't know about what happens when people start eating less of it.

The study1, published in JAMA Psychiatry, included 20 adults diagnosed with depression who regularly consumed large amounts of ultra-processed foods.

Participants were around 44 years old on average, and 70% were women. All also had at least one metabolic health concern, such as high blood pressure, elevated cholesterol, or insulin resistance.

Researchers divided participants into two groups. One continued eating their usual diet for four weeks, while the other followed a diet low in ultra-processed foods, with guidance from the research team.

After four weeks, the groups switched, allowing researchers to compare how participants felt during each dietary period.

Participants purchased and prepared their own food, making the experiment more reflective of everyday life. They were also asked to keep their medications, therapy, exercise, and sleep habits consistent throughout the study.

During the low-ultra-processed-food period, participants reduced their intake of ultra-processed foods by more than 85%. And their mental health scores changed, too. Compared with their usual diets, participants experienced moderate to large improvements across three measures of depression, along with modest improvements in anxiety symptoms.

What's particularly interesting is that participants weren't starting a new medication or therapy. They were simply changing what they ate, while keeping their other routines as consistent as possible.

For context, ultra-processed foods include things like packaged snacks, sugary drinks, fast food, and many ready-to-eat meals. These products often contain ingredients you wouldn't typically use in your own kitchen, such as artificial flavors, emulsifiers, and preservatives.

Of course, there are a few things to keep in mind. This was a small study with just 20 participants, and its main purpose was to see whether people could realistically stick to a diet lower in ultra-processed foods. The researchers also couldn't say exactly what drove the improvements. Was it eating fewer additives, getting more nutrients, or some combination of dietary changes?

One possible explanation involves the relationship between our gut and brain. Our digestive system and brain communicate constantly through nerves, hormones, immune signals, and other pathways. Researchers have become particularly interested in how gut health and inflammation might influence mental health.

The UCSF team proposed that certain ultra-processed foods could disrupt the gut's protective lining, potentially allowing substances to trigger low-grade inflammation throughout the body. That inflammation may, in turn, influence processes involved in depression.

It's an interesting theory, although this study didn't directly measure gut barrier function or establish inflammation as the reason participants' symptoms improved. Researchers also couldn't isolate which dietary changes mattered most. Reducing ultra-processed foods might change someone's intake of fiber, added sugar, fats, calories, and food additives all at once.

In other words, there may be several overlapping explanations for the improvements.

These findings don’t mean you need to throw out everything in your pantry or swear off packaged foods. Start with what feels realistic. Make your favorite dinner from scratch, swap a sugary snack for something with protein and fiber, or try adding a few more minimally processed foods to your grocery cart.