Food and Mood: How Diet Affects Mental Health

Food and Mood: How Diet Affects Mental Health

Anxiety and depression rank among the most prevalent mental health conditions globally. Many people struggling with these issues seek solace in their preferred comfort foods, whether it’s ice cream, pizza, pastries, or double-stuffed Oreos.

While these high-fat, sugar-laden foods might provide momentary comfort, recent research indicates that eating them might ultimately make things worse. 

These findings stem from a developing area of study called nutritional psychiatry, which examines the connection between diet and mental well-being.[*] Research indicates that our daily dietary choices can profoundly impact our mental health, affecting mood, cognitive function, and even the risk of developing mental disorders.

But how exactly does this connection work, and what can we do to harness the power of nutrition for better mental well-being? Join us as we delve into the latest scientific findings on this exciting topic. 

Nutritional Psychiatry Research Demonstrates a Diet-Mood Connection 

Although nutritional psychiatry is still a relatively new field of research, experts have already recognized some fascinating connections in this domain. Here are a few examples:

  • A review from 2015 suggests a connection between the consumption of highly processed foods and a heightened risk of depression.[*]
  • Another 2015 study found that consuming nutrient-poor foods instead of nutrient-dense alternatives (e.g., choosing granola bars over fruits and vegetables) can deprive the brain of essential nutrients, leading to irritability.[*]
  • A review conducted in 2020, which analyzed 61 studies, discovered that for certain individuals, merely boosting their intake of fruits and vegetables led to enhancements in mental health and emotional well-being.[*]
  • A 2019 study asserts that specific nutrients may serve as supplementary treatments for depression. The research indicated that omega-3 fatty acids (EPA and DHA) ameliorated depressive symptoms in patients. Adequate consumption of folate, vitamin B12, and vitamin D also seemed to reduce the risk of depression.[*]

How Does Diet Affect Mental Health?

The big question is “why?” Why do pizza, sweet treats, and chips appear to hinder mental health while fruits, veggies, and legumes seem to enhance it?

We don’t have a definitive answer to this question (yet), but there are a number of theories based on sound research:

#1: Inflammation

Many researchers posit that the inflammatory effects of specific dietary patterns could explain the link between diet and mental health.[*][*]

This theory is bolstered by the observation that diets that support mental health often include high amounts of fruits, vegetables, whole grains, and healthy fats—all of which are rich in anti-inflammatory compounds.[*]

#2: Gut-Brain Connection

Another possible explanation is the gut-brain connection. The foods you eat affect the bacteria in your gut, referred to as the gut microbiome. A healthy diet promotes a healthy gut microbiome, which communicates with the brain through what's called the gut-brain axis.[*

Microbes in the gut also produce feel-good neurotransmitters like serotonin and dopamine, which regulate our moods and emotions. In fact, healthy bacteria in the gut produce approximately 90 percent of the neurotransmitter serotonin, which affects mood.[*] 

#3: Blood Sugar Swings

A growing body of evidence points to a connection between mood and blood sugar highs/lows.

Individuals who consume a diet rich in refined carbohydrates and added sugars may experience a blood sugar rollercoaster—rapid increases in blood sugar levels, followed by an excessive insulin response, followed by acute hypoglycemia (low blood sugar).[*

Symptoms experienced during this blood sugar rollercoaster have been shown to closely resemble mental health symptoms, such as irritability, anxiety, and worry.[*]

What Foods Can Improve Mental Health? 

By consuming nutrient-dense foods associated with better mental health, you can positively affect your mood. The following food groups have been shown to be particularly helpful in supporting mental health. 

#1: High-Fiber Foods

High-fiber foods can support a steady and positive mood due to the blood-sugar-balancing properties of fiber. Fiber aids in slowing down carbohydrate digestion, which prevents blood sugar spikes and subsequent crashes.[*] 

Healthy, high-fiber foods include rolled oats, quinoa, brown rice, amaranth, barley, beans, legumes, starchy veggies, and starchy fruits.

#2: Fermented Foods 

Fermented foods are abundant in essential probiotics, which contribute to the health of your gut—and better gut health is linked to better mood.[*] 

Fermented foods include sauerkraut, kimchi, yogurt, kefir, kombucha, tempeh, and miso.

#3: Foods High in Essential Fatty Acids

Essential fatty acids, particularly omega-3s and omega-6s, are vital fats that must be acquired through your diet, as your body cannot generate them on its own. Omega-3s have been associated with a decreased likelihood of depression and anxiety.[*]

Some foods high in essential fatty acids include fatty fish, flaxseed, pumpkin seeds, walnuts, avocados, and olives. 

#4: Antioxidant-rich Foods

Antioxidant-rich foods play a crucial role in supporting mental health due to their ability to combat oxidative stress and inflammation in the brain.[*]

Some of the top antioxidant-rich foods include berries, dark leafy greens and other vegetables, olive oil, spices, and dark chocolate.

#5: High-Protein Foods

The neurotransmitters in your brain, such as serotonin and dopamine, depend on amino acids derived from protein sources.

High-quality protein sources include lentils, beans, tofu, whole grains, nuts, seeds, wild-caught fish, grass-fed or free-range meat, and high-quality protein powder or protein bars like IQBAR.

Foods to Drastically Reduce or Avoid 

Just as important as knowing which foods to consume more of is knowing which foods to decrease. Here are the top foods linked to low moods and mood disorders.

  • Foods rich in refined sugar: Eating too much refined sugar is linked to an increased risk of brain inflammation and mood disorders.[*][*] Some foods high in refined sugar include candy, pastries, cake, cookies, and soda.
  • Foods high in trans fats: Trans fat consumption has been linked to an increased risk of depression.[*] Some foods high in trans-fats include fried foods, fast food, microwave popcorn, commercial baked goods, stick margarine, and shortening.
  • Highly-processed foods: Research suggests a connection between the consumption of highly processed foods and a heightened risk of depression.[*] Some examples of highly-processed foods include soda, ice cream, sweetened breakfast cereals, packaged soups, and hot dogs.
  • Alcohol: Despite the initial mood boost you may feel, alcohol is a depressant, and excessive consumption has been linked to mood disorders like anxiety and depression.[*]

A Final Word on Diet and Mental Health

While we can’t control factors like our genetic makeup or unforeseen traumatic events, we can manage our dietary choices. That’s really empowering if you think about it! By opting for healthy foods, you can proactively influence your physical and mental well-being, paving the way for a more content and fulfilling life.

While fresh, whole foods should make up the bulk of your balanced diet, it’s always a good idea to keep nutrient-rich convenience foods on hand, such as IQBAR—a vegan and keto protein bar. IQBAR is formulated around five brain nutrients shown to support improved brain function and brain health.

Choose from flavors like Chocolate Sea Salt, Peanut Butter Chip, Banana Nut, Matcha Chai, and Lemon Blueberry. Not sure which flavors to choose? Try our 7-Bar Sampler to find your faves!


Written by Katie Koschalk, a health and wellness writer, certified holistic nutritionist, and certified personal trainer based in California.