Nutrition, Mental Health and Running: How we can improve our moods through proper nutrition during a Pandemic (Part 2)

Written by Rachel Hannah, Registered Dietitian, University of Guelph, Health & Performance Centre. Hannah ran her debut marathon in 2:33:30 in the 2015 Ottawa Marathon. Presented by xact nutrition.


Hi Runners, if you didn’t read the first part of this article then I invite you to read it here. As I explained in the first part of this article, there is a link between diet and mental health. Nutritional psychiatry is a growing field and describes the brain, gut, and mood connection. (You can read more about it here). It is well recognized that eating fruit and vegetables can benefit physical health. Newer studies are proposing that it may also benefit psychological well-being. 

According to a study from the University of Leeds, eating more fruit and vegetables can improve psychological well-being and life satisfaction. Researchers looked at data from over 45,000 people in the UK and found a positive association between the quantity of fruit and vegetables eaten and self-reported mental well-being. The study controlled for other factors that might affect mental well-being such as age, income, education, lifestyle and health, and other foods eaten such as dairy and bread. This study was longitudinal meaning it can relate changes in fruit and vegetable consumption to changes in self-reported well-being for the same individual over time (in this case, 2010-2017). 

Fruits and vegetables tend to be carbohydrate dense and there is some research to suggest that the positive effects of consumption could be partially related to increased concentrations of serotonin in the brain. This study was observational so it can only draw an association and can’t demonstrate cause and effect. There are so many benefits to encouraging better dietary habits for physical health in the long run, and now we are getting more evidence that it can improve mental well-being and life satisfaction as well, in the short run. 

A high performance wellness podcast called “Eat Move Think” by Shaun Francis of Medcan, one of the world’s leading health and well being companies has an episode on how food affects how we think. Dr. Felice Jacka is one of the world-renowned experts on Nutrition Psychiatry and spoke with Shaun on episode 2 to discuss how diet affects our mental health. Leslie Beck is a Registered Dietitian and Medcan’s Director of Food and Nutrition, describes how Nutritional Psychiatry is changing the way we think about mental health from this emerging field: Recognizing that the foods we put in our bodies impact brain function, emotions and moods. 

Observational research is showing the quality of our diet is linked to some mental health disorders. A trial named the Supporting the Modification of Lifestyle in Lowered Emotional States (SMILES) was done at the Food and Mood Centre at Deakin University in Australia. Sixty-Seven participants with major depression were split into two groups, one who followed the Mediterranean diet plus help from a Registered Dietitian. The second group was a social support group with no diet modifications. After three months, the dietary intervention group had a significant improvement in depression and anxiety symptoms. Dr. Felice Jacka coined the term Nutritional Psychiatry and is a principal investigator in the SMILES trial. It was the first intervention like this and took people with clinical depression and helped them make improvements to their diet, resulting in a profound impact on depression scores. You can read more about the results and trial here. 

The Mediterranean diet is the most studied dietary pattern with strong accumulated evidence for health benefits (i.e., cardiovascular, cancer, diabetes, dementia and depression). It is a diet that is high in diverse plant foods. Many other diets are also considered to be notably health-positive, like the Norwegian diet, Japanese, and Chinese diets, to name a few. 

We know what a healthy diet comprises: high in diverse plant foods, quality proteins, and unsaturated fats. It is proposed that we should strive for a “plant predominate” diet. The gut is our second brain since it has its own nervous system. Microbiotic bacteria in our gut play an incredibly important role in our health as they help us digest dietary fibre. Bacteria break food down through a process of fermentation and release a vast range of metabolites, interacting with every cell in the body and influencing the immune system and brain plasticity. The gut can’t do what it is supposed to do in normal physiological functions without dietary fibre. The ketogenic diet has gained recent popularity and is the opposite of what is healthy for the gut. Read more about research on the link between gut and brain health. 

Having long gaps in between meals can also affect energy levels and mood. The term “hangry” combines ‘hungry’ and ‘angry’ and refers to getting short tempered when you haven’t recently eaten. Some who have tried intermittent fasting will know what this feels like and this affects short term mood. The brain needs an adequate supply of energy from blood glucose to concentrate. In fact, the brain uses up 20% of all energy needed by the body! The glucose in our blood comes from all the carbohydrates we eat (fruit, vegetables, whole grains, and lactose in milk products). 

When we eat breakfast and meals containing some carbohydrates consistently throughout the day (no longer than about 4 hour gaps in between meals/snacks), we have enough glucose in our blood. Running and other forms of exercise will use this for energy along with carbohydrates stored in the form of glycogen in our muscles and liver. Our bodies can only store a certain amount of carbohydrates so once we run out, that is when we start to feel tired, weak and even ‘fuzzy minded.’ This state of low blood sugar (hypoglycemia) will impact how hard we can run, meaning we will need to slow down or sometimes stop all together during long and hard efforts. It will also negatively affect our mood and how we recover. 

When runs start to get over 90 – 100 minutes in duration, it is important to consume carbohydrates during activity to ensure good concentration and overall performance. Runs also feel very hard when in a ‘depleted’ state and could further impact mood if someone is already concerned about experiencing mood issues. 

A few suggestions for a healthier gut, improved mood and energy levels: 

  • Our diet should contain a wide variety of protein and vitamin/mineral containing foods in order to support the body’s functions. The best quality carbohydrate sources come from fruits, vegetables, whole grains, legumes, and milk products. Brighter is better so strive for colour and variety in your meals and snacks. 
  • Eat enough fibre and include whole grains and legumes. 
  • Eat whole foods and minimize or avoid packaged or processed foods which have food additives and preservatives that can disrupt the healthy bacteria in the gut. Occasional treats are fine, but try to plan them out and not make them a daily occurrence. 
  • Include probiotic rich foods like kefir and plain yogurt. 
  • When our mood is low, energy levels can also be down. Since healthy eating requires time, energy and planning, sometimes we may rely on more processed foods at meals and snacks. But by learning about how diet can affect our mood/energy levels, hopefully this is motivating enough to make some changes to incorporate more vegetables, fruit and whole grains into the diet. Reach out to me if you want more suggestions on ways to incorporate more vegetables into your diet and I can help! 
  • Start paying attention to how foods make you feel, not just in the moment but the next day. Reflect after cooking a healthy meal on how it makes you feel. If you notice improvements or any positive emotional response after either from yourself or from the loved ones you shared the food with, this could help encourage you to keep practicing this healthy behaviour. 

If your body is deficient in some vitamins and minerals it could affect mood, brain function and energy levels. 

  • Iron deficiency can cause lethargy and a weak feeling. This should be monitored with bloodwork and anemia requires supplementation due to low absorption from food sources. Here is a guide with examples of iron rich foods. 
  • Vitamin B12, B1 or B3 deficiency(s) can cause tiredness and feeling depressed or irritable. B12 comes from animal proteins in meat/fish, eggs and dairy and from fortified foods including whole grain cereals. 
  • Folate deficiency can increase the chance of feeling depressed, particularly in older people. Food sources include green vegetables, oranges and other citrus fruits, beans and fortified breakfast cereals.
  • Selenium deficiency may increase the occurrence of negative mood states and possibly feelings of depression. Food sources include brazil nuts, meat, fish, seeds and whole grain bread. 
  • Minimize long gaps in the day without eating and aim to eat about every 4 hours. 
  • During runs over 90 minutes, fuel with a carbohydrate source during the activity. 
  • Check out this free course called “Food and Mood: Improving Mental Health Through Diet and Nutrition.”

Simply changing your dietary intake pattern doesn’t completely translate into a cure for mental illness, but what we eat does impact depressive symptoms, our mood and energy levels. Improving your whole diet matters most for benefiting mental health. After all, the building blocks of what our brain is made of is nutrients, so make sure you are fueling it properly each day we eat, move, think and live! 

For more information about any details of this article or to discuss further ideas please contact me at: 



Ocean, N, Howley, P & Ensor, J. (2019) Lettuce be happy: A longitudinal UK study on the relationship between fruit and vegetable consumption and well-being. Social Science & Medicine, 222: 335-345


O’Neil, A, et al., (2013) A randomised, controlled trial of a dietary intervention for adults with major depression (the “SMILES” trial): study protocol. BMC Psychiatry, 13(114). 


Strasser, B, Gostner, JM and Fuchs, D. (2016) Mood, food and cognition: role of tryptophan and serotonin. Current Opinion in Clinical Nutrition and Metabolic Care, 19(1):55-61. doi:10.1097/MCO.0000000000000237