Could what’s on your plate affect your mood? A small study from the University of California, San Francisco suggests cutting back on ultra-processed food may help people with depression – though the researchers are clear it’s an early result.
What they did
- 20 adults took part, average age 44, most of them women. All had depression symptoms, a high BMI and at least one metabolic condition.
- Each person spent four weeks on their usual diet and four weeks on a diet low in ultra-processed food, in a different order depending on their group.
- During the low-processed phase, participants cut ultra-processed food by more than 85%, choosing and buying their own food with guidance from the research team.
What they found
After switching diets, participants showed moderate to large improvements across three different measures of depression, and modest improvements in anxiety.
What counts as ultra-processed?
Broadly, foods made mostly from industrial ingredients and additives rather than whole foods – think many packaged snacks, sugary cereals, fizzy drinks, ready meals and processed meats. Cooking from basic ingredients is the simplest way to cut back.
The catch
This was a small pilot study without a randomized control group in the usual sense, and participants knew what they were eating. Twenty people is far too few to draw firm conclusions. The team is planning a larger trial, with enrollment expected in 2028.
Diet changes shouldn’t replace treatment for depression. If you’re struggling, speak to your GP or a mental health professional.
This article is for general information, not medical advice.