Diet and Mental Health: What to Eat for a Better Mood

What you eat can have a direct effect on how you feel. Growing research shows that food is not only fuel for your body, but also for your brain. Understanding the link between diet and mood can help you take small, manageable steps toward supporting your mental wellbeing. From everyday food choices to personalised testing, there are practical ways to use nutrition as part of your mental health toolkit.

How diet influences mood and mental wellbeing

Your brain relies on a steady supply of nutrients to function well. A diet filled with fruit, vegetables, wholegrains, lean proteins, and healthy fats provides the vitamins and minerals needed for stable energy and clear thinking. Diets that are high in processed foods, sugar, and saturated fats have been linked to a higher risk of low mood and anxiety symptoms.

Studies show that adopting traditional diets, such as the Mediterranean diet, are associated with lower rates of depression and anxiety compared with highly processed “Western” diets. These diets often include fish, nuts, legumes, and leafy greens - foods that support brain health and help reduce inflammation that can influence mood.

Foods that can boost your mood

Some nutrients and food groups stand out for their ability to support mental wellbeing. Including these in your daily meals may provide a natural lift:

Omega-3 fatty acids: Found in oily fish, walnuts, and flaxseeds, omega-3s are linked to improved mood and reduced risk of depression.
B vitamins: Folate (in leafy greens and beans) and B12 (in dairy, eggs, meat) support energy production and brain chemistry.
Polyphenols: Colourful plant compounds in berries, dark chocolate, and green tea may help reduce inflammation and improve brain function.
Wholegrains: Provide slow-release energy and help balance blood sugar, which stabilises mood.
Fermented foods: Yogurt, kefir and kimchi contain probiotics that support gut health, which plays a role in mood regulation.

The gut-brain connection

Your gut and brain communicate closely through what is called the gut-brain axis. Trillions of bacteria in the gut influence how neurotransmitters such as serotonin are produced. Around 90% of serotonin - the “feel-good” chemical - is made in the gut. A diverse, fibre-rich diet supports these beneficial gut microbes and, in turn, supports mental wellbeing.

Disruption to gut health, such as through food intolerances or sensitivities, can cause digestive discomfort and may also affect mood. Identifying and adjusting for these sensitivities can therefore be a powerful step in supporting both physical and mental health.

Diet and anxiety: the role of caffeine

Caffeine, found in coffee, tea, and energy drinks, can make anxiety worse for some people, but not for everyone. Genetics play a part. For instance, people with the ADORA2A, rs5751876 genetic variant may feel more anxious after consuming caffeine because their body processes it differently. This genetic marker increases sensitivity, making caffeine’s effects stronger. It highlights how your unique biology can shape the way food and drink affects your mental health.

Role of at-home testing

Personalised insights can help you understand how your body responds to certain foods and drinks. MyHealthChecked’s Intolerances & Sensitivities DNA Test can identify genetic markers, such as those linked to caffeine sensitivity, and highlight foods your body may struggle to digest. This knowledge can empower you to make dietary adjustments that support not only your digestion but also your mood and wellbeing.

By learning how your unique genetic makeup influences your response to foods, you can make choices that reduce discomfort, minimise triggers for low mood or anxiety, and create a diet that supports long-term mental health.

What simple lifestyle steps can support your mood with food?

You don’t need to overhaul your entire diet overnight. Small, consistent changes can make a difference to how you feel day to day. Here are some realistic steps you can start with:

Eat more plants: Add an extra serving of fruit or vegetables to one meal a day. For example, throw a handful of spinach into your omelette or have an apple with your afternoon tea. Over time, these additions increase fibre and essential nutrients that support brain health.
Choose balanced snacks: Instead of reaching for biscuits or crisps, try pairing protein and healthy fats with your carbs. A small handful of nuts with fruit or oatcakes with hummus helps keep blood sugar steady, avoiding the dips that can affect mood.
Cook at home more often: Preparing meals from scratch means you control what goes into your food. Even two or three home-cooked dinners per week can lower your reliance on processed foods and give you a chance to experiment with mood-supporting ingredients such as oily fish, beans, or leafy greens.
Stay hydrated: Mild dehydration can leave you feeling tired and unfocused. Aim for regular water intake throughout the day, especially if you drink caffeinated drinks that have a diuretic effect.
Set a caffeine cut-off: Notice whether coffee or tea later in the day impacts the quality of your sleep, or makes you feel jittery or unsettled. If it does, try switching to decaf after lunch to avoid disrupted sleep or heightened anxiety.
Support your gut: Include fibre-rich foods such as oats, beans, and vegetables daily. Adding small amounts of fermented foods, like kefir can help nourish gut bacteria, which in turn supports mood regulation.
Build steady routines: Eating regular meals, rather than skipping and then overeating, helps keep your energy and mood stable. Keeping consistent times for meals can make a surprising difference to how balanced you feel.

In summary

Food and mood are closely linked. Diets rich in whole foods, omega-3s, B vitamins, and fermented foods can support mental wellbeing, while highly processed diets may contribute to low mood. Gut health plays a key role in how food affects mood, and genetics can influence how substances like caffeine affect anxiety. MyHealthChecked’s Intolerances & Sensitivities DNA Test offers personalised insights, helping you identify foods that may negatively affect your mental wellbeing and guiding you towards positive dietary changes.

Reviewed by Dr Dave Nichols

References

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2. Jacka FN, O’Neil A, Opie R, et al. A randomised controlled trial of dietary improvement for adults with major depression (the ‘SMILES’ trial). PLOS ONE. 2017;12(2):e0169629. https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0222768

3. Jacka FN, Pasco JA, Mykletun A, et al. Association of Western and Traditional Diets with Depression and Anxiety in Women. Am J Psychiatry. 2010;167(3):305–11. https://ajp.psychiatryonline.org/doi/full/10.1176/appi.ajp.2009.09060881

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