This Eating Habit Is Hurting Your Brain & New Research Explains Why
Think about the last packaged snack you grabbed, the drive-through order on a busy night, or the ready-made meal you heated up because you didn't have time to cook.
These are what researchers call ultra-processed foods (UPFs), and they now make up a significant chunk of what most people eat every day. In the U.S., they account for more than half of the average adult's daily calories.
Most of us have heard that processed food isn't great for us. But a new review published in Nutrition Reviews went further than most, tracking 13 different health outcomes across both children and adults to map just how wide the damage goes.
About the review
Ultra-processed foods are industrial products made from refined ingredients and additives, things like added sugars, refined starches, emulsifiers, flavorings, and preservatives that you wouldn't typically find in a home kitchen.
Think: packaged snacks, fast food, flavored drinks, ready-made meals, and many breakfast cereals.
To understand what eating a lot of these foods actually does to the body, researchers screened 81 existing meta-analyses (large studies that pool results from many individual studies) and selected 12 lead publications covering 13 health outcomes. Their evidence spanned research published through December 2025 and included both children and adults.
Eating more UPFs raises your risk across the board
Across almost every health outcome the researchers looked at, eating more ultra-processed foods was linked to worse outcomes. That includes type 2 diabetes, heart disease and high blood pressure, cognitive decline, depression, dental problems, cancer, and dying earlier from any cause.
The clearest finding was on type 2 diabetes. For every 10% increase in the share of your diet that comes from ultra-processed foods, your risk of type 2 diabetes goes up by 10%.
There was no threshold where the risk leveled off; the relationship was consistent all the way up. This was also the only outcome in the review rated as high-certainty evidence, meaning researchers are most confident in this finding.
Higher UPF intake has also been linked to increased Crohn's disease risk, showing just how wide the impact on the body can be.
On heart health, the review found a higher risk of total cardiovascular disease and high blood pressure with greater UPF consumption.
When researchers looked at specific conditions like coronary heart disease, heart failure, or stroke individually, the links were less clear, but the overall cardiovascular picture still pointed in the same direction.
What UPFs do to your brain & mood
People who ate more ultra-processed foods had a higher risk of cognitive decline, meaning problems with memory, focus, and thinking.
A separate analysis found a 32% higher risk of depression among those with the highest UPF intake compared to those with the lowest.
The anxiety picture is more nuanced. In children, higher junk food intake was linked to a greater risk of anxiety, though this finding came from a small number of studies and was rated as low-certainty evidence.
In adults, the review found no significant link between UPF consumption and anxiety, so while it's worth watching, the current evidence doesn't confirm it as a clear outcome for grown-ups.
Diet and mental health are closely connected, and the data on anxiety and diet continues to evolve.
It's also worth keeping in mind that most of the studies in this review were observational, meaning they show associations rather than direct cause and effect.
That said, the consistency of findings across 13 different health outcomes strengthens the overall case.
How to start eating fewer ultra-processed foods
Cutting back on UPFs doesn't mean reworking your entire diet overnight. A few practical starting points:
- Check the ingredient list, not just the nutrition label: Ultra-processed foods tend to have long ingredient lists packed with additives, preservatives, and flavor enhancers you wouldn't find in a home kitchen. That's a more reliable signal than fat or sugar content alone.
- Swap one thing at a time: Pick the UPF you eat most often and find a simpler alternative. Swapping packaged snacks for nuts, fruit, or yogurt is a small change with a real impact.
- Cook more, even minimally: Simple meals made from whole ingredients (a grain bowl, scrambled eggs, fruit with nut butter) count as far less processed. You don't need to be a chef to eat better.
- Don't trust "healthy" packaging: Many products marketed as nutritious (protein bars, flavored oat packets, plant-based meat alternatives) are still ultra-processed. The ingredient list tells the real story.
The takeaway
The evidence is clear and growing: ultra-processed foods are linked to a wide range of serious health outcomes, from type 2 diabetes and heart disease to depression and cognitive decline. The data on type 2 diabetes suggests that every reduction counts, no matter how small.