How does what we eat impact our mental health?

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Introduction

We often hear about eating for physical health, but food and nutrition also play an important and increasingly recognised role in mental wellbeing. Growing evidence suggests that what we eat may influence mood, stress, focus, sleep and emotional wellbeing through several interconnected systems within the body.^1,2

The foods we eat provide much more than calories. They supply nutrients, fibre and healthy fats and naturally occurring plant compounds called phytonutrients that help support brain function, regulate inflammation, nourish beneficial gut bacteria and maintain stable energy levels. Together, these systems can influence how we think, feel and respond to everyday challenges.^1,2

In this blog, we explore how food may influence mental wellbeing through four interconnected biological systems:

Brain function and neurotransmitter production
Gut health and the gut-brain axis
Blood sugar and energy regulation
Inflammation and immune function

These systems do not operate independently. For example, the gut microbiome influences inflammation, inflammation can affect brain function, and blood sugar regulation can influence both mood and stress responses.

Together, these interconnected systems influence mood, stress, concentration, motivation and emotional wellbeing. Many of the same foods support several of these systems at the same time, which is why overall dietary patterns are often more important than individual foods or nutrients.^1,3

We also explore practical, evidence-informed ways to support your mental wellbeing through food.

Nutrients help the brain function

The brain needs a steady supply of nutrients to produce neurotransmitters (chemical messengers), maintain brain cells and support communication between different parts of the brain. These processes influence mood, focus, memory, motivation and emotional regulation.

Several nutrients play important roles in supporting brain health and mental wellbeing, including omega-3 fatty acids, B vitamins, magnesium, zinc, iron, vitamin D and the amino acids tryptophan and tyrosine. Deficiencies in some of these nutrients have been associated with poorer mental health outcomes, although they are rarely the only factor involved. Correcting a deficiency is different from assuming that supplements will improve mental health in people who already have adequate nutrient levels.^1,3

Where can you find these nutrients?

Most people can obtain these nutrients through a varied, balanced diet.³

Omega-3 fatty acids: Oily fish such as salmon, mackerel, sardines and herring are rich sources of EPA and DHA. Plant foods including flaxseeds, chia seeds, walnuts and hemp seeds provide ALA, which the body can convert into EPA and DHA, although only in small amounts. For people following vegetarian or vegan diets, algal oil supplements can provide a direct plant-based source of DHA, and some also provide EPA. Check the product label for the types and amounts of omega-3 fatty acids provided.^4,5
B vitamins (B6, B9 and B12): Found in leafy green vegetables, legumes, wholegrains, eggs, dairy products, fish and meat. Vitamin B12 is found naturally almost exclusively in animal products, including seafood, meat, dairy and eggs. People following vegan diets, and some vegetarians, may need fortified foods such as nutritional yeast, fortified plant milk and fortified breakfast cereals, or a B12 supplement.⁶
Magnesium: Found in foods such as pumpkin seeds, chia seeds, almonds, cashews, Brazil nuts, beans, lentils, oats, brown rice, spinach and kale. Magnesium helps support healthy nervous system function and plays a role in many processes involved in brain health.³
Zinc: Found in meat, seafood, dairy products, beans, lentils, chickpeas, pumpkin seeds, sesame seeds and cashew nuts. Zinc supports healthy nervous system function and plays an important role in brain development, communication between brain cells and immune health.³
Iron: Found in red meat, poultry, fish, beans, lentils and tofu. Iron helps carry oxygen around the body and is essential for energy production, concentration and cognitive function. Plant-based sources are absorbed less efficiently, so pairing them with vitamin C-rich foods, such as citrus fruits or peppers, can help improve absorption.⁶
Vitamin D: Found naturally in oily fish, egg yolks and some fortified foods. However, sunlight remains the primary source of vitamin D for most people in the UK. Vitamin D supports brain function, immune health and a range of biological processes involved in mood regulation.^3,6
Tryptophan and tyrosine: Found in protein-rich foods such as fish, eggs, dairy products, poultry, beans, lentils, soy foods, nuts and seeds. These amino acids act as building blocks for neurotransmitters, including serotonin and dopamine, which help regulate mood, motivation and emotional wellbeing.¹

How does gut health affect mental health?

The gut–brain connection

The gut and brain are closely connected through the gut-brain axis, a two-way communication network linking the digestive system and the brain.⁷

Although most of the body’s serotonin is produced in the gut, this serotonin cannot cross into the brain. Instead, the gut microbiome influences brain function indirectly through:

Nutrient metabolism
Immune signalling
Gut-brain communication

The trillions of microorganisms that make up the gut microbiome play an important role in this relationship. A healthy and diverse microbiome helps to:^7,8

Support communication between the gut and brain
Regulate immune function and inflammation
Maintain the gut lining and gut barrier, helping prevent unwanted substances from passing from the gut into the bloodstream and triggering unnecessary immune and inflammatory responses
Produce beneficial compounds, including short-chain fatty acids (SCFAs), which help maintain the gut lining, regulate inflammation and support communication between the gut and brain.⁸
Influence the systems involved in mood, stress and emotional wellbeing

Research suggests that poorer gut health and reduced microbial diversity may be associated with an increased risk of depression and anxiety.⁷

How can you support your gut microbiome?

There are several practical ways to help support a healthy and diverse microbiome:

Aim for 30 or more different plant foods each week: Different plants provide different types of fibre and phytonutrients that nourish different groups of beneficial gut bacteria. Many phytonutrients, including polyphenols and flavonoids, also have antioxidant properties that help protect cells from oxidative stress and support healthy inflammatory responses. Together, these compounds help support a more diverse microbiome and the production of beneficial short-chain fatty acids (SCFAs), which maintain the gut lining, regulate inflammation and support communication between the gut and brain. Fruits, vegetables, legumes, wholegrains, nuts, seeds, herbs and spices all count towards this total.9
Eat plenty of fibre: Fibre acts as a food source for beneficial gut bacteria, helping them produce short-chain fatty acids (SCFAs), including butyrate, acetate and propionate. These compounds help maintain the gut lining, support immune function, regulate inflammation and contribute to communication between the gut and brain.8 This is one reason why diets rich in fibre-containing foods such as vegetables, fruits, legumes, nuts, seeds and wholegrains are associated with better overall health and may support mental wellbeing.
Include fermented foods: Some fermented foods, especially live yoghurt, kefir and unpasteurised fermented vegetables, contain live microorganisms that may help support microbial diversity and gut health. Some products, including pasteurised or cooked fermented foods, may contain few or no live microorganisms.10

How does blood sugar affect mood and energy?

Why does blood sugar matter?

The brain depends heavily on glucose for energy. In healthy people, the body normally keeps blood glucose within a relatively narrow range. The effects of ordinary post-meal changes in blood glucose on mood, energy and concentration vary between people, and the evidence is mixed. True hypoglycaemia is a separate medical condition, most often linked to diabetes treatment, and should not be confused with normal changes after eating.^1,11

Foods containing rapidly absorbed carbohydrates can produce larger rises in blood glucose after eating. Meals that combine higher-fibre carbohydrates with protein and healthy fats are digested more slowly and can help provide more sustained energy. For some people, this may also help avoid large fluctuations in hunger and concentration.^1,3

How can you support stable energy levels?

Some practical ways to support more sustained energy include:³

Wholegrains: Foods such as oats, brown rice, quinoa and wholegrain bread provide fibre and complex carbohydrates. They tend to be digested more slowly than refined carbohydrates and can provide a more gradual release of energy.
Protein-rich foods: Foods such as fish, lean meats, eggs, dairy products, pulses and tofu can help with fullness and may slow digestion when eaten with carbohydrate-containing foods.
Healthy fats: Foods such as nuts, seeds, extra-virgin olive oil and avocado can slow digestion when included in mixed meals and also provide nutrients that support brain and overall health.
Regular meals and snacks: Eating regular meals, and planned snacks where helpful, may help some people maintain more consistent hunger and energy patterns.

Diet can influence inflammation

Inflammation is a normal part of the body’s defence system and plays an important role in protecting us from infection and injury.

However, when inflammation becomes chronic and persists at low levels over time, it may affect brain function, mood and emotional wellbeing.¹²

Growing evidence suggests that chronic low-grade inflammation has been associated with:

Depression
Anxiety
Fatigue
Reduced cognitive performance

Certain dietary patterns may contribute to inflammation, while others may help regulate it.¹³

Dietary patterns high in ultra-processed foods and refined sugars, and low in fibre and micronutrients, may influence health through several interconnected pathways, including oxidative stress, blood sugar regulation, the gut microbiome and inflammatory signalling. These pathways are complex and are still being studied.

One pathway researchers are particularly interested in is oxidative stress. This occurs when unstable molecules called free radicals build up faster than the body can neutralise them. Over time, oxidative stress can damage cells and contribute to chronic low-grade inflammation. Diets rich in fruits, vegetables, herbs, spices and other plant foods provide antioxidants and phytonutrients that help protect cells from oxidative stress and support healthy inflammatory responses.

How can food help regulate inflammation?

Research suggests the following dietary habits may help support healthy inflammatory responses:

Eat a wide variety of plant foods: Fruits, vegetables, legumes, nuts and seeds provide fibre, antioxidants and phytonutrients that help support immune function and regulate inflammation. Many of these compounds also help protect cells from oxidative stress, which can contribute to chronic inflammation over time.
Include omega-3-rich foods: Omega-3 fats, particularly EPA and DHA, help regulate inflammatory pathways in the body and are associated with anti-inflammatory effects. Oily fish are among the richest sources, while flaxseeds, chia seeds and walnuts provide ALA, another type of omega-3 fat.^4,14
Support gut health: A healthy and diverse gut microbiome helps regulate immune responses and maintain the gut barrier. This may help reduce unnecessary inflammation and support healthy communication between the gut and brain. Eating a variety of fibre-rich plant foods and including fermented foods where possible can help support gut health.
Reduce ultra-processed foods where possible: Diets high in ultra-processed foods are often lower in fibre and important nutrients while being higher in ingredients that may promote inflammation. Research has linked higher intakes of ultra-processed foods to poorer gut health, increased inflammation and greater fluctuations in energy levels.¹⁵

Why are ultra-processed foods a concern for mental health?

Ultra-processed foods (UPFs) are often discussed in relation to mental health because they may influence several of the biological systems linked to wellbeing at the same time. Rather than acting through one single mechanism, they may affect gut health, inflammation, nutrient intake and blood sugar regulation simultaneously.¹⁵

Many commonly consumed ultra-processed foods are lower in fibre and important micronutrients while being higher in refined carbohydrates, added sugars, unhealthy fats and ingredients designed to improve shelf life, texture or flavour. Over time, dietary patterns high in these foods may place additional strain on the body’s interconnected biological systems.

Possible pathways include:

Lower fibre intake and less support for beneficial gut bacteria
Reduced production of beneficial compounds such as short-chain fatty acids (SCFAs)
Poorer gut barrier function and increased inflammatory signalling
Lower intake of some vitamins and minerals needed for healthy brain function
Greater fluctuations in blood sugar and energy levels
Increased oxidative stress and chronic low-grade inflammation

Not all ultra-processed foods are equally harmful, and occasional consumption within an overall balanced diet is unlikely to have a significant impact. However, replacing some ultra-processed foods with nutrient-dense whole foods may help support several of the biological systems associated with mental wellbeing.¹⁵

Do overall eating patterns matter more than individual foods?

There is no single food that can prevent or treat mental health conditions. Instead, research suggests that overall dietary patterns are more important than any individual nutrient or so-called “superfood”.¹˒²

Rather than focusing on individual foods, it can be more helpful to think about how your overall eating pattern supports the biological systems linked to mental wellbeing. A balanced diet can help:

provide the nutrients needed for healthy brain function
support a diverse and healthy gut microbiome
regulate inflammation
promote more stable energy levels throughout the day.

Many foods support several of these systems at once. For example, fruits, vegetables, legumes, nuts and seeds provide fibre that nourishes beneficial gut bacteria, phytonutrients and antioxidants that help regulate inflammation, and vitamins and minerals that support healthy brain function.

The Mediterranean diet is one of the most extensively studied dietary patterns in the world. It emphasises vegetables, fruits, legumes, wholegrains, nuts, olive oil and fish, and has been associated with better physical health and lower rates of depression. Many of the foods included in this dietary pattern support several of the biological systems discussed throughout this article.¹⁶^˒¹⁷

Eating a wide variety of foods also increases dietary diversity, making it more likely you’ll obtain the range of nutrients, fibre and phytonutrients needed to support both physical and mental health.

The goal is not to eat perfectly. Small, sustainable changes that increase dietary variety and nutrient intake can help support both physical and mental wellbeing over time.³

Four ways to support your mental wellbeing through food

Aim for 30 different plant foods each week

Increasing the variety of plant foods you eat helps provide a wider range of fibre, vitamins, minerals and phytonutrients while supporting a healthy, diverse gut microbiome.

Eat fibre-rich foods every day

Wholegrains, beans, lentils, fruit and vegetables feed beneficial gut bacteria, helping produce short-chain fatty acids (SCFAs) that support gut health, inflammation regulation and communication between the gut and brain.

Include omega-3-rich foods regularly

Oily fish provide EPA and DHA, while flaxseeds, chia seeds and walnuts provide ALA. Together, these omega-3 fats support brain function and help regulate inflammation.

Reduce ultra-processed foods where possible

Replacing some ultra-processed foods with whole or minimally processed alternatives can support gut health, inflammation regulation and more stable energy levels.

Food for thought: everyday eating for long-term mental health

Food influences much more than physical health. The foods we eat help support the interconnected systems that contribute to mental wellbeing, including brain function, gut health, inflammation, energy regulation and immune function.

While nutrition alone cannot prevent or treat mental health conditions, it is one of the everyday factors that can help support long-term mental wellbeing. Small, sustainable changes, such as eating a wider variety of plant foods, including more fibre and omega-3-rich foods, and reducing ultra-processed foods where possible, can all contribute to a healthier dietary pattern.

At the same time, food choices are not made in isolation. Household income, food insecurity, the local food environment, education, access to school meals and wider social inequalities all influence what people are able to eat. Schools, food banks, community organisations, local authorities and national policy therefore all have an important role to play in ensuring everyone has access to affordable, nutritious food that supports both physical and mental health.^{18, 19}

Supporting mental wellbeing through nutrition is not about achieving a perfect diet. It is about creating environments where healthier choices are realistic, accessible and sustainable for everyone.

References:

Firth J, Gangwisch JE, Borsini A, Wootton RE, Mayer EA. Food and mood: how do diet and nutrition affect mental wellbeing? BMJ. 2020;369:m2382. doi:10.1136/bmj.m2382
Firth J, Marx W, Dash S, Carney R, Teasdale SB, Solmi M, et al. The effects of dietary improvement on symptoms of depression and anxiety: a meta-analysis of randomized controlled trials. Psychosomatic Medicine. 2019;81(3):265-280. doi:10.1097/PSY.0000000000000673
NHS. The Eatwell Guide. Accessed 3 July 2026. https://www.nhs.uk/live-well/eat-well/food-guidelines-and-food-labels/the-eatwell-guide/
National Institutes of Health Office of Dietary Supplements. Omega-3 fatty acids: fact sheet for health professionals. Accessed 3 July 2026. https://ods.od.nih.gov/factsheets/Omega3FattyAcids-HealthProfessional/
NHS. Fish and shellfish. Accessed 3 July 2026. https://www.nhs.uk/live-well/eat-well/food-types/fish-and-shellfish-nutrition/
NHS. The vegan diet. Accessed 3 July 2026. https://www.nhs.uk/live-well/eat-well/how-to-eat-a-balanced-diet/the-vegan-diet/
Cryan JF, O’Riordan KJ, Cowan CSM, Sandhu KV, Bastiaanssen TFS, Boehme M, et al. The microbiota-gut-brain axis. Physiological Reviews. 2019;99(4):1877-2013. doi:10.1152/physrev.00018.2018
Silva YP, Bernardi A, Frozza RL. The role of short-chain fatty acids from gut microbiota in gut-brain communication. Frontiers in Endocrinology. 2020;11:25. doi:10.3389/fendo.2020.00025
McDonald D, Hyde E, Debelius JW, Morton JT, Gonzalez A, Ackermann G, et al. American Gut: an open platform for citizen science microbiome research. mSystems. 2018;3(3):e00031-18. doi:10.1128/mSystems.00031-18
Wastyk HC, Fragiadakis GK, Perelman D, Dahan D, Merrill BD, Yu FB, et al. Gut-microbiota-targeted diets modulate human immune status. Cell. 2021;184(16):4137-4153.e14. doi:10.1016/j.cell.2021.06.019
NHS. Low blood sugar (hypoglycaemia). Accessed 3 July 2026. https://www.nhs.uk/conditions/low-blood-sugar-hypoglycaemia/
Miller AH, Raison CL. The role of inflammation in depression: from evolutionary imperative to modern treatment target. Nature Reviews Immunology. 2016;16(1):22-34. doi:10.1038/nri.2015.5
Chen GQ, Chen YY, Wang XS, Li Y, Deng YT, Cao YF, et al. Association between Dietary Inflammatory Index and mental health: a systematic review and dose-response meta-analysis. Frontiers in Nutrition. 2021;8:662357. doi:10.3389/fnut.2021.662357
Dyall SC, Balas L, Bazan NG, Brenna JT, Chiang N, da Costa Souza F, et al. Polyunsaturated fatty acids and fatty acid-derived lipid mediators: recent advances in the understanding of their biosynthesis, structures and functions. Progress in Lipid Research. 2022;86:101165. doi:10.1016/j.plipres.2022.101165
Lane MM, Gamage E, Du S, Ashtree DN, McGuinness AJ, Gauci S, et al. Ultra-processed food consumption and mental health: a systematic review and meta-analysis of observational studies. Nutrients. 2022;14(13):2568. doi:10.3390/nu14132568
Lassale C, Batty GD, Baghdadli A, Jacka F, Sanchez-Villegas A, Kivimaki M, Akbaraly T. Healthy dietary indices and risk of depressive outcomes: a systematic review and meta-analysis of observational studies. Molecular Psychiatry. 2019;24(7):965-986. doi:10.1038/s41380-018-0237-8
Jacka FN, O’Neil A, Opie R, Itsiopoulos C, Cotton S, Mohebbi M, et al. A randomised controlled trial of dietary improvement for adults with major depression (the SMILES trial). BMC Medicine. 2017;15:23. doi:10.1186/s12916-017-0791-y
Pourmotabbed A, Moradi S, Babaei A, Ghavami A, Mohammadi H, Jalili C, et al. Food insecurity and mental health: a systematic review and meta-analysis. Public Health Nutrition. 2020;23(10):1778-1790. doi:10.1017/S136898001900435X
Department for Environment, Food & Rural Affairs. United Kingdom Food Security Report 2024: theme 4, food security at household level. Accessed 3 July 2026. https://www.gov.uk/government/statistics/united-kingdom-food-security-report-2024

Where to get help

If you need further advice on supporting yourself or a young person with their mental health, take a look at the services below that can help.

Looking for local support?

If you’re based in the East of England, these NHS wellbeing hubs offer free tools, advice and services to support your mental health:

Cambridgeshire and Peterborough Wellbeing Hub (H.A.Y)

Suffolk Wellbeing Service

You can find self-help guides, local activities, talking therapies and more.

How does what we eat impact our mental health?

Jump to section:

Introduction

Nutrients help the brain function

Where can you find these nutrients?

How does gut health affect mental health?

The gut–brain connection

How can you support your gut microbiome?

How does blood sugar affect mood and energy?

Why does blood sugar matter?

How can you support stable energy levels?

Diet can influence inflammation

How can food help regulate inflammation?

Why are ultra-processed foods a concern for mental health?

Do overall eating patterns matter more than individual foods?

Four ways to support your mental wellbeing through food

Aim for 30 different plant foods each week

Eat fibre-rich foods every day

Include omega-3-rich foods regularly

Reduce ultra-processed foods where possible

Food for thought: everyday eating for long-term mental health

Where to get help

Looking for local support?

Samaritans

Parenting Mental Health

Explore more from our blog

Inflammation and mental health: What it is, why it matters and how to reduce it

Stress, cortisol and mental health

Gut health and mental health: understanding the gut–brain connection

How exercise supports our mental health

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