Researchers are testing whether a special diet called the MIND diet can help people lose weight and feel better mentally. The study involves 126 adults in Sweden who will either follow the MIND diet (which focuses on brain-healthy foods) or get regular diet advice for 12 weeks. Scientists will track their weight, mood, stress levels, and the bacteria in their gut—because what we eat affects all of these things. This research could help doctors understand why people who struggle with weight often also struggle with depression and anxiety, and whether changing what you eat can improve both problems at the same time.

The Quick Take

  • What they studied: Whether following the MIND diet (a diet designed to support brain health) can help people lose weight, improve their mood, reduce stress and anxiety, and change the healthy bacteria in their gut.
  • Who participated: 126 adults in Sweden who are overweight or have obesity (BMI of 30 or higher). Half will follow the MIND diet, and half will receive standard dietary advice.
  • Key finding: This is a study plan, not yet completed research. The researchers want to see if the MIND diet is practical for people to follow for 12 weeks and whether it helps with weight loss and mental health.
  • What it means for you: If this study works well, it could lead to a new way to help people manage both weight and mental health problems together. However, results won’t be available until the study is finished and analyzed.

The Research Details

This is a randomized controlled trial, which is considered one of the strongest types of research. Researchers will randomly assign 126 adults to two groups: one group follows the MIND diet (which emphasizes foods like leafy greens, berries, nuts, fish, and whole grains while limiting red meat and processed foods), and the other group receives general healthy eating advice. Both groups will aim to eat fewer calories—less than 2,300 calories per day for men and less than 1,900 for women. The study lasts 12 weeks, and researchers will collect information at the beginning and end.

The MIND diet was originally designed to support brain health and reduce the risk of dementia. Researchers chose this diet because they believe it might help with both weight loss and mental health. The study will measure how many people stick with the diet, how satisfied they are with it, and whether it actually works.

Researchers will also collect stool samples to study the bacteria living in participants’ guts. These bacteria, called the microbiota, play an important role in digestion, immunity, and even mood. By comparing the bacteria before and after the diet change, scientists hope to understand one way that food affects our mental health.

This research approach is important because it tests whether the MIND diet actually works for real people in real life, not just in theory. By measuring both physical changes (weight loss) and mental changes (mood, stress, anxiety), researchers can see if improving one area helps the other. Understanding the gut bacteria connection could explain why people with weight problems often have mental health challenges, and it might lead to better treatments.

This is a well-designed study because it uses randomization (random assignment to groups), which reduces bias. The study includes both objective measurements (weight, body measurements) and subjective ones (mood, stress levels). Researchers will also conduct interviews to understand people’s experiences. However, this is a relatively small study (126 people) and only lasts 12 weeks, so results may not apply to everyone or show long-term effects. The study is being conducted in Sweden, so results might differ in other countries with different food cultures.

What the Results Show

This is a study protocol (a plan for research), not yet completed research, so there are no results to report yet. The researchers have not yet conducted the study or collected data from participants. The primary goal is to see whether the MIND diet is feasible—meaning whether people can stick with it, whether they follow the instructions, and whether they’re satisfied with the program.

Once the study is completed, researchers will measure how many people stayed in the study from beginning to end (retention), how well people followed the diet plan (adherence), and what people thought about the experience (acceptability). These measurements will help determine if the MIND diet is practical enough to test in a larger study.

The secondary measurements will examine whether people lost weight, whether their waist size decreased, whether their mood improved, and whether their stress and anxiety levels went down. Researchers will also look at changes in the types and amounts of bacteria in the gut.

Beyond weight loss and mood, researchers will measure several other health markers: body mass index (BMI), waist and hip measurements, and body fat percentage. They’ll also assess mental health more thoroughly by measuring perceived stress, depression symptoms, and anxiety symptoms. The gut bacteria analysis will show whether the MIND diet changes the diversity and types of bacteria in the digestive system, which could explain how diet affects mental health.

Previous research suggests that the MIND diet may help protect brain health and reduce dementia risk. Other studies show that obesity and mental health problems often occur together, and that what we eat affects both our weight and our mood. This study is unique because it specifically tests whether the MIND diet can address both problems at the same time and explores the gut bacteria connection. If successful, it would build on existing research showing that diet, gut health, and mental health are all connected.

This study has several important limitations to consider. First, it’s relatively small (126 people), so results may not apply to everyone. Second, it only lasts 12 weeks, which is not long enough to see if benefits continue over months or years. Third, the study is being done in Sweden, so results might be different in other countries where people eat different foods or have different healthcare systems. Fourth, people who volunteer for diet studies might be more motivated than the general population, so results might not apply to people who are less interested in changing their diet. Finally, this is a study plan, not completed research, so we don’t yet know if the MIND diet will actually work for weight loss and mental health.

The Bottom Line

This is preliminary research that hasn’t been completed yet, so there are no evidence-based recommendations to make at this time. However, the MIND diet itself is based on existing research showing it supports brain health. If you’re interested in trying the MIND diet, it emphasizes foods like leafy greens, berries, nuts, fish, whole grains, beans, and olive oil while limiting red meat, butter, cheese, and processed foods. As always, talk to your doctor before making major diet changes, especially if you take medications or have health conditions. (Confidence level: Low, pending study results)

This research is most relevant to adults who are overweight or have obesity and who also struggle with depression, anxiety, or stress. It may also interest people who want to improve their brain health and mental wellbeing through diet. Healthcare providers, nutritionists, and mental health professionals should pay attention to these results when they’re published. People with serious mental health conditions should continue working with their mental health providers rather than relying on diet changes alone.

This study won’t be completed for several months after the initial 12-week intervention period, as researchers need time to analyze the data and write up their findings. Even if the diet does help, most people don’t see significant weight loss or mood improvements in just 12 weeks—it typically takes 4-8 weeks to notice changes, and 3-6 months to see substantial results. Long-term benefits (beyond 12 weeks) are unknown from this study.

Want to Apply This Research?

  • Track daily mood (using a simple 1-10 scale), stress level (1-10 scale), and anxiety symptoms (number of anxious moments per day) alongside meals eaten and calories consumed. This helps you see if changes in what you eat correlate with changes in how you feel mentally.
  • If you want to try the MIND diet approach, use the app to log meals that emphasize leafy greens, berries, nuts, fish, whole grains, and beans while tracking your mood and stress. Start by adding one MIND-diet food group per week rather than changing everything at once, making the change more manageable.
  • Set weekly check-ins to review your mood and stress trends alongside your diet patterns. After 4 weeks, assess whether you notice any changes in energy, mood, or anxiety. Continue tracking for at least 12 weeks to give the diet enough time to potentially show effects, similar to the research study timeline.

This article describes a research study plan, not completed research results. The MIND diet and its effects on weight loss and mental health have not yet been proven by this specific study. This information is for educational purposes only and should not replace professional medical advice. If you’re struggling with obesity, depression, anxiety, or other mental health conditions, please consult with your doctor or mental health professional before making significant dietary changes. Diet alone is not a substitute for mental health treatment. Always talk to your healthcare provider before starting a new diet, especially if you take medications or have existing health conditions.