Researchers studied over 13,000 young people in China to see if eating different types of foods affects depression. They found that students and teenagers who ate a wider variety of foods—like vegetables, fruits, and soy products—had fewer signs of depression. The more diverse their diet, the better their mood seemed to be. This suggests that simply eating different healthy foods, rather than the same meals over and over, might be a simple way to help protect mental health during important growing years.

The Quick Take

  • What they studied: Does eating a variety of different foods help reduce depression symptoms in young people?
  • Who participated: 11,856 college students and 1,281 children and teenagers in China, ranging from elementary school age through college age
  • Key finding: Young people who ate the most variety of foods had much lower rates of depression—college students with the most diverse diets had about 67% lower odds of depression compared to those eating very limited foods
  • What it means for you: Eating different types of healthy foods—especially vegetables, fruits, and plant-based proteins—may help protect your mood and mental health. This is a simple, practical step you can take, though it’s not a replacement for professional mental health care if you’re struggling.

The Research Details

This was a cross-sectional study, which means researchers looked at a large group of people at one point in time and asked them about their eating habits and mood. All participants filled out questionnaires about what they ate and whether they experienced depression symptoms. The researchers then looked for patterns between diet variety and depression rates.

The study used two different depression screening tools to measure mood symptoms—one called the PHQ-9 and another called the SDS—to make sure they were accurately identifying depression. They also collected information about other factors that might affect mood, like exercise, sleep, and stress, so they could focus specifically on the diet connection.

The researchers used a special statistical method to analyze the data that allowed them to account for differences between people (like age, gender, and lifestyle) to see if diet really was the key factor.

This research approach is important because it looks at real-world eating patterns in a large, diverse group rather than just studying one small group. By examining different age groups separately—children, teenagers, and college students—the researchers could see if diet affects mood differently at different life stages. This helps us understand whether nutrition matters more at certain ages.

Strengths: This study included a very large number of participants (over 13,000), which makes the findings more reliable. The researchers measured depression using established, validated tools rather than just asking one question. They adjusted their analysis for other factors that might affect mood.

Limitations: This was a snapshot study, so we can’t prove that eating variety actually causes better mood—only that they go together. The study only included Chinese participants, so results might be different in other populations. All information came from self-reported questionnaires, which means people might not remember or accurately report what they ate or how they felt.

What the Results Show

Among college students, depression was present in about 19 out of every 100 students. Those who ate the most variety of foods had significantly lower depression rates. Specifically, students who ate foods from 9 different food groups had about 67% lower odds of depression compared to those eating from almost no food groups.

Among younger children and teenagers, depression was less common (about 5 out of 100), but the pattern was even stronger. Those eating from 7 different food groups had about 97% lower odds of depression compared to those eating from almost no food groups.

When looking at specific foods, college students who regularly ate vegetables had about 33% lower odds of depression, those eating fruit had about 22% lower odds, and those eating soy products had about 11% lower odds. Children and teenagers showed similar benefits from eating fruits and also benefited from eating breakfast regularly.

The study found that fried food consumption was associated with higher depression symptoms in children and adolescents, suggesting that not all foods have the same effect. The protective effect of dietary diversity appeared stronger in younger age groups, suggesting that nutrition might be especially important during childhood and teenage years when the brain is still developing.

Previous research has suggested links between diet and mental health, but this is one of the first studies to look at dietary diversity specifically across different age groups. The findings align with other research showing that plant-based foods like vegetables and fruits are beneficial for mood, and they add new evidence that variety itself—eating many different types of foods—may be important, not just eating specific ‘superfoods.’

The biggest limitation is that this study shows correlation, not causation—we can’t say that eating variety definitely causes better mood, only that they’re connected. People who eat diverse diets might also exercise more, sleep better, or have other healthy habits that actually improve mood. The study only included Chinese participants, so we don’t know if these findings apply to other populations with different food cultures. All data came from people’s memories of what they ate, which can be inaccurate. The study didn’t measure depression severity, only whether depression symptoms were present or not.

The Bottom Line

Moderate confidence: Try to eat foods from at least 5-7 different food groups daily. Focus on including vegetables, fruits, whole grains, proteins (including plant-based options like soy), and healthy fats. This is a practical, low-risk strategy that may support mental health alongside other healthy habits. High confidence: This should complement, not replace, professional mental health care if you’re experiencing depression.

This research is most relevant for young people (children through college age) and their parents or guardians looking for practical ways to support mental health. It’s also relevant for school nutrition programs and public health officials designing youth mental health initiatives. Anyone experiencing depression should still seek professional help—this is a supportive strategy, not a treatment.

Changes in mood from dietary improvements typically take several weeks to a few months to become noticeable. Consistency matters more than perfection—gradually increasing food variety over time is more sustainable than trying to change everything at once.

Want to Apply This Research?

  • Track the number of different food groups eaten each day (vegetables, fruits, grains, proteins, dairy/alternatives, etc.) with a goal of reaching 5-7 different groups daily. Also track mood using a simple 1-10 scale to see if you notice patterns over 4-8 weeks.
  • Use the app’s meal planning feature to suggest recipes that include ingredients from different food groups. Set daily reminders to ’eat the rainbow’ by including at least one colorful vegetable or fruit at each meal. Create a shopping list that automatically includes variety from multiple food groups.
  • Weekly check-ins comparing dietary diversity scores to mood ratings. Monthly summaries showing trends in both metrics. Alerts if dietary diversity drops below target levels, with suggestions to reintroduce variety. Long-term tracking (3-6 months) to identify personal patterns between eating habits and mood stability.

This research suggests an association between dietary diversity and lower depression symptoms, but it does not prove that changing your diet will cure or treat depression. If you or someone you know is experiencing depression, please consult with a healthcare provider or mental health professional for proper evaluation and treatment. Dietary changes should be considered a complementary strategy alongside, not a replacement for, professional mental health care. Always consult with a doctor or registered dietitian before making significant dietary changes, especially if you have existing health conditions or take medications.