How our Diet Impacts our Mental Health

We’ve all heard the saying “you are what you eat,” but did you know your brain might agree? Research increasingly shows that what we eat affects not only our physical health but also how we feel mentally. And while the idea that food can influence mood might sound intuitive, the ways diet can impact mental health and wellbeing may surprise you. Let’s take a closer look.

The Gut-Brain Connection

Your gut and brain are in constant communication through what’s known as the gut–brain axis – a superhighway of nerves, hormones, and chemical messengers connecting your digestive system and your brain (1–3).

Your gut houses trillions of microbes (the gut microbiome), which are shaped by the foods you eat. In return, they produce compounds that can influence mood, immunity, and stress responses. For instance:

Certain gut microbes help create neurotransmitters like serotonin and gamma-aminobutyric acid (GABA) – key regulators of mood and stress (2–4).
When you eat high-fibre foods, beneficial microbes produce short-chain fatty acids (SCFAs) that can help reduce inflammation and support brain health (5,2,3).
The gut microbiome also influences the HPA (hypothalamic-pituitary-adrenal) axis, which plays a role in how we respond to stress through affecting cortisol levels (6,1).

Research Spotlight: A 2025 review highlighted that diet-driven changes to the gut microbiota can strongly affect emotional, cognitive, and general well-being (7).

In short: a healthy gut helps support a healthy mind.

Dietary Patterns Linked with Mental Wellbeing

Many dietary patterns linked to better mental health share one thing in common: plants and fibre.

However, it’s important to keep in mind that most studies only show associations rather than being able to prove cause and effect. This is because other factors, including lifestyle habits like sleep, exercise, and social connection, can also play a role in mental health – and sometimes, mood can influence eating habits too. Viewing findings as promising but not proven can be helpful while the science continues to evolve.

Plant-Based and Mediterranean Diets

Plant-based diets – rich in fruits, vegetables, wholegrains, legumes, nuts, and olive oil – are consistently linked to better mental wellbeing and lower rates of depression (8–12).

One particularity famous trial – The SMILES trial – found when adults with major depression followed a Mediterranean-style diet for 12 weeks, they had significantly greater improvements in depressive symptoms compared to those who just received social support. Around 32% even achieved remission vs only 8% in the social support arm (8).

That said, if you’re following a vegan or vegetarian diet, whilst these dietary patterns are recognised as healthy for all ages and life stages, additional care should be taken to ensure you’re getting enough of certain key nutrients (e.g., vitamin B12, iron, and omega-3 fatty acids) (14). Low levels can contribute to fatigue or low mood, so planning and, where needed, supplementation under medical supervision are key (15).

For more infomation on plant-based diets, check out our Vegan Nutrition Hub.

Foods we should eat less of

No food or food group should be off-limits – there is a place for all foods to be enjoyed in moderation. But when it comes to looking purely at the evidence on mental wellbeing, research consistently links ultra-processed foods, such as sugary snacks, sweetened drinks, fast foods, and refined grains, with higher rates of depression and anxiety (16–18).

Again, while these studies cannot prove causation, most experts agree that limiting ultra-processed foods in favour of more whole or minimally processed options supports both physical and mental wellbeing.

Nutrients of Focus

Whilst no single nutrient is a cure-all, certain nutrients have been shown to play a role in brain health and mood regulation when working in synergy with an overall healthy diet and lifestyle:

Omega-3 Fatty Acids (EPA & DHA): Found in oily fish, walnuts, flaxseeds, and chia seeds, Omega-3s are linked to reduced depressive symptoms, especially alongside antidepressants (19).
B Vitamins: Essential for nerve function and neurotransmitter synthesis, deficiencies in B vitamins may contribute to mood disturbances (20), and one review found supplementation may help reduce stress (21).
Zinc: Deficiency is associated with increased risk of depression, whilst supplementation is associated with reduced risk of depressive symptoms (22,23).
Antioxidants: Found in colourful plant-foods, these compounds were shown in one meta-analysis to be ‘associated with improved depression and anxiety states’ (25).
Dietary fibre: Can support gut health, which, as discussed above may support mental health.

How to put it into practice:

Start small: gradually replace processed foods with plant alternatives (e.g., swap half the meat in dishes like spaghetti bolognese for lentils or beans (and maybe even add some chopped carrots and walnuts!).
Increase fibre gradually: if you’re not used to eating a high-fibre diet, increase intake gradually to avoid discomfort. Equally, if you have IBS or IBD, consult with a registered dietitian first.
Try fermented foods: foods like tempeh, kimchi, sauerkraut, kefir, yoghurt, and even sourdough bread may contain live microbes that can support gut health (24). Just opt for unsweetened and minimally processed options, where possible.
Be mindful of key nutrients: If your diet is lacking in ‘The Nutrients of Focus’, consider looking over your meals to see where you can add in some dietary sources (e.g., adding omega-3-rich ground flaxseeds to your overnight oats, or Vitamin-B12-rich nutritional yeast to your pasta sauces). Additionally, consult with your healthcare practitioner about whether supplementation is needed.
Limit ultra-processed foods: Try simple, home-made swaps for your favourite packaged snacks and products.

Conclusion

What we eat can influence how we feel, and the foods that support our mood often mirror national healthy eating guidelines. You don’t need to be perfect – small, consistent dietary changes can have a positive impact on your mental wellbeing. Perhaps just making time to care for yourself through food is part of what makes you feel better! Remember though, diet is of course just one piece of the puzzle. If you are struggling with your mental health, please reach out for professional help or therapy.

Here are some resources you might find useful:

Dietitian’s Disclaimer:

The information in this article is provided by Amber Woodhouse, Registered Dietitian, and is based on current scientific evidence. It is intended for general educational and informational purposes for the general adult public and does not replace dietetic advice. Any references to foods or products are illustrative examples only and do not constitute specific endorsements from myself. Readers should consult with their healthcare provider before making significant dietary changes, particularly if they have a medical condition. If you’re concerned about your mental health, please speak with a GP or registered healthcare professional.

Meal Shakesexpand_moreMeal Shakes

Protein Shakesexpand_moreProtein Shakes

Vegan Shakesexpand_moreVegan Shakes

Weight Loss Shakesexpand_moreWeight Loss Shakes

Muscle & Gainer Shakesexpand_moreMuscle & Gainer Shakes

Health & Wellnessexpand_moreHealth & Wellness

Focus & Energy Shakesexpand_moreFocus & Energy Shakes

Accessoriesexpand_moreAccessories

Breakfastexpand_moreBreakfast

Sweetexpand_moreSweet

Savouryexpand_moreSavoury

Nut Butters & Spreadsexpand_moreNut Butters & Spreads

Feel Betterexpand_moreFeel Better

Health & Wellnessexpand_moreHealth & Wellness

Weight Lossexpand_moreWeight Loss

Creatineexpand_moreCreatine

Vitamins & Mineralsexpand_moreVitamins & Minerals

Pre Workoutsexpand_morePre Workouts

Amino Acidsexpand_moreAmino Acids

Omega 3expand_moreOmega 3

Dietary Patterns Linked with Mental Wellbeing

Plant-Based and Mediterranean Diets

Foods we should eat less of

Nutrients of Focus

How to put it into practice:

Conclusion

Mushroom Coffee

Magnesium Glycinate X3

Creatine 360

Dietitian’s Disclaimer:

References:

Related Posts