Food and mood - by Katy Stuart, RD
The relationship between food and our mood is complex and influenced by many factors. Not only does food provide us with the necessary nutrients for our bodies to function, but it can also affect how we feel emotionally and our state of well-being.[1]
Our brains use 20% of our daily calorie intake (estimated 400 calories a day) and the brain is made up of 60% fat (cholesterol and polyunsaturated fats such as omega-3s).[2] The brain needs a constant supply of energy to function optimally and specific nutrients are needed for neurotransmitters and hormones.[3] It makes sense that what we eat and drink will have an impact on our cognitive functioning and mood.[1,3,4]
In turn, our mood can influence our eating habits.[1] Food is not just fuel. It can be used as a reward, to show kindness and care, and to give us comfort and pleasure. It may have significant cultural or religious associations for us, and food choices can be influenced by childhood experiences, family and friends, as well as social media. [1,3-6]
How food can affect mood and mental health
Consuming a diet lacking nutrient-rich foods can affect our energy levels and our mood.[1] As well as a regular supply of energy, the brain requires protein and micronutrients, including B vitamins, to produce monoamine neurotransmitters such as serotonin, norepinephrine and dopamine.[2,7] These neurotransmitters have important functions in the brain in regulating mood, motivation, alertness, sleep, appetite and memory.[8]
Vitamin B deficiency is known to cause tiredness, irritability and depression.[5] Folate and zinc deficiency are also thought to affect mood and cognitive ability,[2] while selenium deficiency can increase feelings of low mood and depression.[9]
Glycaemia can affect mood, especially with extreme highs and lows. The brain relies on glucose for energy and fluctuations will trigger hormone responses, such as spikes in adrenaline, leading to mood changes.[10,11] There is clinical evidence that glycaemic variability and persistent hyperglycaemia or hypoglycaemia are linked to an increased risk of depression and anxiety and have a severe impact on quality of life, especially for those with diabetes.[11]
Essential fatty acids, omega-3 and omega-6 modulate dopamine and serotonin pathways in the brain and have anti-inflammatory and neuroprotective effects.[2] They form part of the nerve cell membranes and are required for the central nervous system to function.[2] Omega-3 fatty acids are effective in the treatment of mental health conditions such as ADHD, major depressive disorder, bipolar depression and PTSD.[2,12]
As well as specific nutrient deficiencies, research shows that diets high in unhealthy fats and added sugars can increase the risk of developing depression and anxiety.[4,6] Observational clinical trials have shown there is an inverse relationship between diet quality and symptoms of depression, and high sugar consumption can have an adverse effect on long-term psychological health.[4,11] It is widely accepted now that having a balanced diet is important for the treatment and prevention of mental illness.[13]
Caffeine and alcohol
Those of us who regularly drink tea, coffee and other caffeinated drinks know the effects this has on our mood, which is usually positive, helping us feel awake and alert. However, too much caffeine (or for those who are sensitive to its effects) can lead to anxiety, palpitations and disturbed sleep. [1,3,14,15] Caffeine withdrawal can also lead to irritability and headaches, although this is usually temporary.[3]
Alcohol is a known depressant, and excessive alcohol intake can affect brain function, cognition and mood.1,3,14] Specifically, alcohol disrupts the neurotransmitters gamma-aminobutyric acid (GABA) and glutamate by increasing the effect of GABA, which has a calming effect initially and then decreases glutamate levels, making you feel less alert and drowsy.[16] The addictive nature of alcohol is due to its effects on the reward centre of the brain by increasing dopamine and serotonin.[17] Over time, excessive drinking can lead to the brain producing less dopamine, so the craving for the ‘high’ from the alcohol increases further.[17]
Alcohol can make us more prone to injuries and accidents, as it is a disinhibitor and lowers our awareness of danger. It also slows down the central nervous system and the parts of the brain involved in decision-making and consideration of consequences.[16,17] Alcohol can lower blood sugar and increase dehydration, affecting our physical and emotional well-being.[16,17]
There is a high risk of nutrient deficiencies with prolonged alcohol use, as it reduces the body’s ability to absorb thiamine and magnesium, which are needed for normal brain function.[16] Severe thiamine deficiency can lead to a serious condition called Wernicke’s encephalopathy, characterised by confusion and ataxia (problems with coordination, balance and speech). If treated quickly with high-dose thiamine it is reversible, but if left untreated can lead to Korsakoff’s syndrome, which is a chronic neurological condition.[18]
The gut-brain axis
The gut-brain axis and the impact of the gut microbiome on mental health is a new area of research.[2,12] We know now from research into the potential causes for irritable bowel syndrome, that anxiety and stress can directly affect gut transit leading to gastrointestinal problems such as constipation, diarrhoea and bloating.[7,15] Changes in gut bacteria known as bacterial dysbiosis may affect mood.[7] For example, a recent study on the use of probiotics (in healthy individuals) showed alterations in the brain's response to tasks that required emotional attention and may reduce symptoms of depression.[10] The beneficial gut bacteria strains of Lactobacillus and Bifidobacterium have been associated with increasing the production of GABA and serotonin, helping to regulate mood and stress responses.[7]
Ultra-processed foods (UPFs) versus fruit and vegetables
Healthy eating patterns, such as the Mediterranean diet, which is high in fruits, vegetables, polyunsaturated fats and wholegrains, is associated with better mental health than a typical ‘Western diet’ characterised by a high intake of processed foods, fats and sugars.[10]
Studies have shown that the Mediterranean eating pattern can reduce inflammatory markers and various mental health conditions have been linked to chronic inflammation.[10] Study participants reported that having an intake of eight servings of fruit and vegetables a day made them feel calmer, happier and more energetic.[4] This indicates the Mediterranean diet can support emotional well-being and lead to better cognitive health.[4,712] UPFs, such as crisps, cakes, biscuits and instant meals, common in Western diets, are thought to impact mental health.[7] One recent study found that the development of anxiety and depression was higher in those who consumed more than five servings a day of UPFs compared with those who had less than three.[7]
Improving mood and mental wellbeing with nutrition
A balanced healthy diet is always the best advice for improving your mental and physical wellbeing. However, here are the top tips for what to eat to help improve your mood:
1. Adopting a ‘Mediterranean’ eating pattern of plenty of fruits, vegetables, wholegrains, legumes, nuts, seeds and olive oil. Also, including some fish and poultry in moderation and limiting red meat, high-fat dairy products and processed foods. [10]
2. Eating enough protein - Tryptophan, an essential amino acid, is required to make neurotransmitters in the brain.[3] It has been theorised that increasing the intake of tryptophan can improve mood. However, there is not enough good-quality evidence to say that eating lots of protein will improve mental health.[1] Certainly, though protein is an important part of the diet. Lean meat, fish, eggs, low-fat dairy products, and plant-based sources such as beans, lentils and chick peas are good choices.[9]
3. Eating regularly and having slow-release energy sources with high fibre content, such as wholegrain bread, cereals, nuts, seeds, brown pasta and brown rice, will help with blood sugar control and can influence mood disorders.[4,9,13,19]
4. Have a good intake of fibre for healthy digestion and higher fibre intake has been associated with lower levels of anxiety and depressive symptoms.[20]
5. Limit caffeine, alcohol and maintain good hydration.[15,19]
6. Have your five a day (or more), which provides plenty of vitamins, minerals and fibre.
7. Include foods that contain omega-3 and omega-6 fatty acids, such as oily fish, i.e. sardines, tuna, salmon and mackerel, seeds and nuts, avocado and vegetable oils. [4,9,14]
8. Plant-based diets provide a good intake of polyphenols and bioactive compounds and these have been shown to have neuroprotective and antidepressant-like properties, which help regulate neurotransmitter activity and improve cognitive function.[7]
9. Include some treats! For example, chocolate is known to improve mood and reduce tension. However, it is better to choose dark chocolate that contains less added fats and sugars.[4]
10. Eating high-quality unprocessed foods that contain lots of vitamins, minerals, and antioxidants nourishes the brain and protects it from oxidative stress.[9,12,13] Reducing UPFs such as crisps, cakes, biscuits, instant meals and takeaway meals.[12]
11. Keep a food and mood diary which may help identify times where you feel low in mood (or your mood is really good!) and this may correlate with what you have eaten that day and your fluid intake.[3]
Conclusion
More research is needed to fully understand the links between food and mental health. We also need a greater understanding of how nutrients can improve mood and well-being.[10] However, it is recognised now that food and diet have an important role to play in brain and cognitive functioning and nutrition and lifestyle advice should be part of the treatment for mental health conditions.[13]
Katy is currently a Specialist Renal Dietitian working in the community. She has 20 years of experience working in the NHS in various roles, including
nutrition support, ICU and renal.
Katy Stuart, RD, Specialist Renal Dietitian
References
British Dietetics Association (2025). Food Facts Food and Mood. https://www.bda.uk.com/resource/food-facts-food-and-mood.html
LaChance L, Ramsey R (2015). Food, Mood, and Brain Health: Implications for the Modern Clinician, Missouri Medicine.https://pmc.ncbi.nlm.nih.gov/articles/PMC6170050/
Mind (2025). Food and Mental Health. https://www.mind.org.uk/information-support/tips-for-everyday-living/food-and-mental-health/
American Heart Association (2023). Food and Mood. https://www.heart.org/en/healthy-living/healthy-lifestyle/mental-health-and-wellbeing/food-and-mood
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Lee M, Angus D, Walsh H, Sargeant S (2011). Maybe it’s Not Just the Food?” A Food and Mood Focus Group Study, Int J Environ Res Public Health. Jan 21;20(3):2011.
Wijesekara T, Xu B (2025). New insights into the connection between food and mood: Unlock the science-backed benefits of dietary bioactive components toward emotional wellbeing, Trends in Food Science and Technology, vol 162. https://www.sciencedirect.com/science/article/abs/pii/S0924224425002419
Blows W (2000). Neurotransmitters of the brain: serotonin, noradrenaline (norepinephrine), and dopamine, Journal of Neurosciences Nursing, 32(4):234-8. https://pubmed.ncbi.nlm.nih.gov/10994538/
Havard Health Publishing (2022). Nutritional psychiatry: Your brain on food by Eva Selhub MD. https://www.health.harvard.edu/blog/nutritional-psychiatry-your-brain-on-food-201511168626
Firth J, Gangwisch J, Borsini A, Wooton R, Mayer E (2020). Food and mood: how do diet and nutrition affect mental wellbeing?, British Medical Journal. https://www.bmj.com/content/369/bmj.m2382
University of Michigan School of Public Health (2019). Is Your Mood Disorder a Symptom of Unstable Blood Sugar? By Isa Kay. https://sph.umich.edu/pursuit/2019posts/mood-blood-sugar-kujawski.html#:~:text=A%20growing%20body%20of%20evidence,brain%20runs%20primarily%20on%20glucose
British Association of Nutrition and Lifestyle Medicine (2022). Connecting the dots between food and mood. https://bant.org.uk/connecting-the-dots-between-food-and-mood/
Food and Mood Centre, Deakin University, Australia, Looking through the lens at how food can improve our mood by Sophie Mahoney. https://foodandmoodcentre.com.au/2021/04/looking-through-the-lens-at-how-food-can-improve-our-mood/
British Nutrition Foundation (2025). Food and Your brain. https://www.nutrition.org.uk/nutrition-for/food-and-thebrain/
Mental Health Foundation (2022). Diet and mental health. https://www.mentalhealth.org.uk/explore-mental-health/a-z-topics/diet-and-mental-health
Royal College of Psychiatry (2024). Alcohol, mental health and the brain. https://www.rcpsych.ac.uk/mental-health/mental-illnesses-and-mental-health-problems/alcohol-mental-health-and-the-brain#:~:text=Brain%20chemistry%20%2D%20Alcohol%20affects%20the,effect%20on%20your%20mental%20health.
Alcohol Change UK (2025). Alcohol and your mood: the highs and lows of drinking. https://alcoholchange.org.uk/alcohol-facts/fact-sheets/alcohol-and-your-mood
Vasan S, Kumar A (2023). Wernicke Encephalopathy, StatPearls. https://www.ncbi.nlm.nih.gov/books/NBK470344/
College of Medicine and Integrated Health (2025). Introducing our Food for Mood Campaign. https://collegeofmedicine.org.uk/our-food-for-mood-campaign/
Deakin University, Australia. The latest on fibre as fuel for your mind and mood. By Hajara Aslam and Sophie Mahoney (2025). https://foodandmoodcentre.com.au/2023/12/the-latest-on-fibre-as-fuel-for-your-mind-and-mood
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