Is food messing with your mood? 4 expert-backed changes to try

What you eat won't ever solve every mental health challenge, but a growing body of evidence shows it can have a surprising impact on mood and stress, thanks to everything from blood sugar crashes to gut health.

Experts explain four simple and practical dietary tweaks to help support mental wellbeing.

While optimising your diet isn't a substitute for professional care when it comes to depression, it can be a valuable part of a holistic treatment.

Prof Felice Jacka, director of the Food and Mood Centre at Deakin University, has spent years studying how diet and depression are linked.

"Extensive and consistent research tells us that healthier diets protect against depression."

That means a diet high in wholegrains, vegetables, fruit, fish and olive oil – similar to the Mediterranean diet.

"A balanced diet feeds the brain, providing it with the nutrients it needs to support a positive mood, and improve signalling pathways between brain cells for optimal brain function," she adds.

Jacka's SMILES trial, external showed adopting a Mediterranean-style diet helped reduce the symptoms of depressive illness.

She's now supporting changes to the Australian healthcare system that will see people with depression get diet and exercise support as part of their treatment.

1. Eat regularly

Eating regularly keeps your blood sugar levels stable. When these drop, we get tired and irritable. Spikes followed by dips have also been linked to mood disorders, external including depression and anxiety.

"If you get hungry often in the day and this affects your mood, concentration and energy levels, then eating at regular intervals is important," says nutritionist and psychologist Dr Sonal Shah.

She suggests eating every three to four hours to keep energy levels up, but warns it's not an excuse for constant grazing as that "doesn't allow the appetite and insulin hormones to regulate optimally."

2. Stay hydrated

When you're thirsty, it's harder to think clearly and focus, external. The brain needs water, says Shah, which explains why you're more susceptible to mental stress when you're dehydrated.

"Water helps blood flow, so if there isn't enough water to help clear the toxins out of the body, this leaves you feeling weak," she explains.

Dehydration also makes us crave unhealthy foods like crisps and refined carbohydrates, says Shah.

Water is usually the best choice for hydrating our bodies, but other fluids do count. Just avoid sugary drinks.

3. Reduce your dependency on ultra-processed foods

Research has found links between diets high in ultra-processed foods and poorer mental health outcomes, although scientists are still investigating exactly why this relationship exists.

Jacka says studies from around the world show diets high in sugar, and those with added fat and salt, are linked to worse mental health as well as heart disease and diabetes, external.

Animal and human studies have also shown these diets can damage the hippocampus – the part of the brain involved in learning, memory and emotional regulation.

We often reach for refined foods, low in vitamins and minerals, when we're already feeling stressed or tired, says Shah, as they give us a "quick high."

If it's a one-off, it's not likely to cause long-term problems, but if it's ongoing it can become a vicious cycle.

But it can be tricky to move away from processed food, says Shah, and it takes more than just willpower.

"It involves changing the tastebuds so they become less tickled by junk food and begin to crave healthier foods… It's also about understanding why you reach for certain foods in the first place.

"Food shouldn't be used to control emotions. Habits and eating behaviours take time to address, and I would recommend working with therapists to establish the reasons for them and heal them," continues Shah.

4. Add more plants to your diet

Scientists have been focusing for years on the role of the gut in fighting depression and research has shown what we eat can help.

"Diet is one of the most important factors affecting the health of the gut and its bacteria," Jacka explains.

"We now know that the gut bacteria (microbiota) play a critical role in the health of our immune system, our metabolism, our gene expression, and our mental and brain health."

Eating a variety of different plant foods could help support a more diverse gut microbiome, which researchers believe can have a significant impact our overall health, including brain health.

Changing ingrained eating habits is no small task. If you want to update your diet to help support your mental health, start with small and achievable tweaks.

It's about building sustainable long-term habits, not just doing a quick overhaul.

Shah advises pairing mental health support with gentle dietary tweaks and keeping a journal to spot patterns between your eating habits and your mood.

If you are concerned about your mental health,help and support is available.

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