Nutrition & Gut Health

People often begin looking at nutrition when they feel low, anxious, exhausted, burnt out or unable to concentrate.

You might notice that you feel irritable when you have skipped lunch, flat after a day of eating on the run, or more settled when you have been eating regularly. You might also be curious about how your gut health connects with your mood.

Nutrition can play a role in supporting:

• Energy and concentration
• Mood and emotional wellbeing
• Physical health and recovery
• Gut health and digestion
• Overall brain health

Research is also exploring dietary approaches alongside care for depression and other mental health conditions. Food is an important part of the picture, and the support each person needs will be different.

The gut-brain connection

Your gut and brain communicate in both directions through pathways involving the nervous system, immune system and hormones. This is known as the gut-brain axis.

Your gut is also home to a vast community of microorganisms, known as the gut microbiome. Researchers are investigating how these organisms interact with digestion, immune function and brain signalling, and what that might mean for mental health.

This is an exciting and fast-growing area. We know the gut and brain communicate; we are still learning exactly how changes in the microbiome affect an individual person's mood, and which treatments reliably help.

You do not need an expensive "gut reset" to begin caring for your gut. Everyday habits, including eating a variety of foods and getting enough fibre, are a practical place to start.

Food and the brain

Your brain needs energy and nutrients to function. A varied eating pattern can help provide protein, healthy fats, vitamins and minerals that support the body and brain.

How and when you eat can matter too. Going long periods without food may leave some people feeling tired, shaky, irritable or unable to focus. Regular meals and snacks can help make energy more manageable throughout the day.

If you notice changes in your mood or energy around food, pay attention with curiosity rather than judgement. Your experience is useful information.

Food and depression: the SMILES trial

In the Australian SMILES trial, 67 adults experiencing moderate to severe depression were offered either dietary support from a dietitian or social support over 12 weeks.

The group receiving dietary support had greater improvements in depression symptoms. Most participants were also receiving other treatment, and the study was relatively small, but it opened an important conversation about nutrition as part of mental healthcare. [1]

A separate review of 16 randomised trials involving more than 45,000 people found that dietary improvements had a small overall benefit for depressive symptoms. The review did not find a clear overall benefit for anxiety. [2]

The findings do not tell us that food alone will resolve depression. They do suggest that nutrition deserves a place in the conversation and in the support people are offered.

An emerging field: ketogenic diets and serious mental illness

Some researchers and clinicians are exploring whether dietary approaches can influence the brain's metabolism and support people living with serious mental illness. This area is often called metabolic psychiatry.

One approach being studied is a ketogenic diet, a high-fat, very low-carbohydrate diet that changes how the body uses energy.

The findings so far are striking enough to take seriously, and early enough that we should say exactly what they are.

In 2022, a group of clinicians looked back at the records of 31 adults living with major depression, bipolar disorder or schizoaffective disorder whose symptoms had not improved despite intensive psychiatric treatment. While in hospital, they followed a ketogenic diet alongside their usual care. Depression scores dropped sharply. Among the ten people living with schizoaffective illness, symptom scores roughly halved. [4]

Those numbers are remarkable. Here is what they cannot tell us. Everyone in that group was also receiving intensive inpatient care, there was no comparison group, and the records were reviewed afterwards rather than planned as a trial. So we cannot know how much of the change came from the diet.

Which is why the next study matters.

In 2026, researchers published the first randomised controlled trial in this field. Fifty-eight people with schizophrenia-spectrum or bipolar I disorder were randomly assigned either to a ketogenic diet or to continue eating as usual for one month, with some continuing for four. Metabolic health improved significantly in the diet group. People with higher ketone levels tended to report fewer symptoms of depression, and that held even after accounting for weight loss. [5]

The researchers were careful about what this shows. One month is probably too short to see mental health change. The longer phase involved fewer people and had no comparison group. They called for larger and longer trials before anyone draws conclusions about treatment.

So something is happening here that deserves proper investigation, and it is finally being investigated.

A ketogenic diet for a mental health condition is a significant dietary intervention, not a general recommendation for everyone. It also needs care alongside psychiatric medication, because weight, blood sugar and medication levels can all shift. If you are interested in exploring it, speak with your treating clinician and a dietitian experienced in this approach.

Nutrition advice can feel overwhelming, especially when you are already exhausted. You do not have to change everything at once. Start with what is achievable and build from there.

Eat regularly where you can

If you frequently forget to eat or get caught up in the day, a little structure can help. That might mean setting a reminder, keeping a snack nearby or creating a few reliable meals you do not have to think about.

Regular eating can make it easier to meet your needs and may help you notice how food affects your energy and concentration.

Add more nourishing foods

Rather than starting with a long list of things to eliminate, consider what you can add:

• Vegetables and fruit
• Wholegrains and legumes
• Protein sources you enjoy, such as eggs, fish, meat, tofu or beans
• Healthy fats, including olive oil, nuts, seeds and oily fish
• Water throughout the day

Variety matters, but it does not have to be expensive or complicated.

Think about your gut

Fibre-rich foods, including vegetables, fruit, wholegrains and legumes, help support digestive health. Some people also enjoy fermented foods such as yoghurt, kefir, kimchi or sauerkraut.

But everyone's gut is different. Foods that feel good for one person can leave another feeling bloated or uncomfortable, particularly if they are experiencing digestive issues. If something does not agree with you, you do not need to force it just because it is considered healthy.

Think of your gut health like a car service. We take our cars in to check what is going on under the bonnet, yet we often keep pushing through when our own bodies are telling us something is not quite right. If you have ongoing digestive symptoms, or simply want to understand your gut health better, a conversation with your GP or an Accredited Practising Dietitian can be a useful place to start.

You may have heard the term leaky gut. Changes in the permeability of the gut lining are a real area of research, but "leaky gut syndrome" is not a standard diagnosis, and there is no established routine test that explains every digestive symptom. [3] A practitioner can help investigate your symptoms and decide which tests, if any, are appropriate for you.

Notice how food affects you

You might find it helpful to gently notice how your mood, energy, digestion and sleep respond to different foods, caffeine or alcohol.

This is not about policing every meal. It is about learning what helps you feel good and recognising patterns without turning food into another source of stress.

If tracking food or focusing closely on what you eat feels distressing, particularly if you have a history of disordered eating, you can skip this and ask a dietitian for support.

Thinking about food takes up a surprising amount of our lives. Deciding what to eat, shopping, preparing, cooking, eating and cleaning up all require time and mental energy.

When you are tired, overwhelmed or caring for everyone else, even deciding what to have for dinner can feel like too much. And when it is late and nothing is prepared, ordering takeaway can become the easiest option.

That is not a lack of willpower. It is a sign that you might need more support and fewer decisions.

Prepare when you have the capacity

You do not need to cook a week's worth of elaborate meals. A little preparation can make a difference:

• Wash or chop a few vegetables.
• Cook extra portions and freeze them.
• Keep simple ingredients for two or three meals you enjoy.
• Have easy snacks available for busy days.
• Make a short shopping list you can reuse.

Share or outsource what you can

If it is available to you, ask a partner, family member or friend to share the planning and preparation, if you have the means outsource weekly help for this. You might arrange a grocery delivery, use prepared ingredients, choose a meal service or ask someone to help you create a simple weekly routine.

An Accredited Practising Dietitian can also help build a plan around your health, budget, preferences and energy levels. The goal is to make nourishing yourself easier to sustain in real life.

And when takeaway is what gets you fed, that is okay too. One meal does not define your health.

If you would like more support, these questions can be a starting point:

• Could an Accredited Practising Dietitian help me?
• Are there any nutrient deficiencies worth checking in my circumstances?
• How might my digestive symptoms, medication or health conditions affect what I need?
• Are any supplements I am considering safe alongside my medication?
• How can I make nourishing meals more manageable with my budget and energy?
• Given my relationship with food, what approaches would you recommend or avoid?