Did you know that 95 percent of our happy hormones actually live in our stomachs? It's for this reason, and so many more, that what we eat can have a massive impact on the way we feel. Putting the right food in your body is important to ensure you get the right fuel, but also so you're looking after your mind, as well as your body.

As the research into plant-based diets increases, we're seeing more and more evidence that this way of life has real benefits. And not just around our physical health, plant-based diets can aid our mental wellbeing too. To find out more, we spoke to ambassador for Inside Out Nutritious Goods, nutritionist and dietitian Millie Padula. Below, she answered all the questions we had about diet, mental health and plant-based eating.

Can our diets have an impact on our mental health? What might these impacts look like?

Our eating patterns can have an immense impact on our mental health, in both a positive or negative way; depending on the overall quality of our diet.

Research has shown that because the food we eat has such a profound effect on our mood and mental health, scientists around the globe are now referring to the gut as the second brain.

The health of our gut can intricately dictate the state of our mind and functioning of our brain via a few different pathways. Firstly, we all have a nerve called the ‘vagus nerve’ which runs directly from our brain to our stomach allowing for bi-directional communication between the two; and explains how both organs are so closely linked. Have you ever experienced ‘butterflies’ in your stomach before? This is an example of the brain communicating with the gut.

Secondly, 95 percent of our serotonin (one of our happy hormones) is located in the gut, so it makes sense that what we eat and the environment in which these cells are found impacts how they perform. A healthy digestive system full of beneficial bacteria from a whole-foods, plant-based diet will positively affect the functioning of serotonin, and vice versa.

Thirdly, most of us can also vouch for the fact that when we fill our bodies with nutritious foods, our energy levels are better, our sleep quality improves and we feel more motivated and optimistic which indirectly affects our mental health for the better.

Research shows that fuelling your body with nutritious foods can reduce your risk of depression based on the above factors. According to several studies, individuals who tend to present with mood disorders such as depression typically consume diets that are far from adequate.

Are the effect psychological or physiological? And is this something that is related to particular foods or food groups - or ways of eating like diet culture?

According to the ‘food and mood’ centre, the diet of an adult is closely correlated with the size of their hippocampus (a part of our brain involves emotional regulation). Those who consumed a healthy, well-balanced diet that contained adequate amounts of fruits, vegetables, lean protein, quality dairy products, complex carbohydrates and healthy fats were more likely to have a larger hippocampus. Perhaps we are what we are after-all.

There is also a prominent link between our mental health and consumption of omega 3 essential fatty acids. DHA and EPA are two types of Omega 3’s which are found in the brain in abundance and appropriate dosages through food or supplementation have proven to be beneficial for depression, bipolar disorders, ADHD, autism and aggression.

Omega 3’s can be found in oily fish such as salmon, tuna, sardines and mackerel, walnuts, chia seeds, linseeds/flaxseeds, hemp seeds and algae.

Another nutrient that can affect our mood is Vitamin B6 - commonly found in chickpeas. Research shows that low intakes of B6 can be associated with depression.

Not surprisingly, more research needs to be conducted in the area of diet and mental health, but the results are looking promising thus far.

Do you think that plant-based diets are beneficial for mental health?

Yes, absolutely! Plant-centric diets and eating patterns focused on the predominant consumption of plants are some of the most well researched and beneficial diets in reference to their effect on our mental health.

Nutritious plant-based diets encompass a wide variety of fruits, vegetables, lentils, legumes, nuts, seeds and whole-grain; in other words - a whole lot of foods full of vitamins, minerals, fibre and other nutritious compounds.

Plant foods are high in dietary fibre, in particular prebiotic fibre which helps to fuel the beneficial bacteria (also known as probiotics) in our gut. This brings me to the food and mood equation, which looks like this: the greater variety of plant foods we eat = the greater variety of beneficial bacteria in the gut = the greater the health outcomes such as improvements in mood and mental health. Inside Out’s Unsweetened Oat Milk contains prebiotic fibre and is a great addition to a nutritious diet and an excellent non-dairy alternative, particularly if you experience gut issues or adverse reactions that are impacted by the consumption of dairy.

When fibre is fermented in our large bowel, it generates what we call a ‘short-chain-fatty-acid’ which is a group of compounds known to have positive effects on inflammation levels, disease risk, immunity and our ability to absorb mood-boosting nutrients from our food.

Could they be more beneficial for mental health than omnivore-style diets? If so, why?

Plants have a greater impact than animal products on our mood, but this isn’t to say that animal foods can’t be a part of a mood-supporting diet. Typically, a plant-based diet allows for small amounts of animal products if the individual permits, so as long as the majority of your diet is derived from nutritious plant-foods, there should be no negative impact imposed on your mental health. If you eat more animal foods than you do plants, your fibre intake will likely be inadequate and will therefore not have much of an impact on your healthy gut bugs and in turn, your mood.

Are plant-based diets something that you encourage people to explore?

Yes, a thousand times over! Here in Australia, most of us just don’t eat enough plants. Whilst we know plants include a wide variety of foods and good groups, just 7% of us manage to meet our vegetable requirements, and put blatantly - that just isn’t enough of us. My dietary recommendations are always centred around eating more vegetables, it sounds so stereotypical of a dietitian, but based on that statistic - can you blame me? As I’ve mentioned, plant consumption is associated with so many wonderful health benefits, everything from our mood and mental health (of course), to our gut health, immune health, inflammatory levels and disease risk.

What do you think is the biggest barrier for people in switching to plant-based eating? And how can we overcome that?

Honestly, I think it’s the ‘all-or-nothing’ approach so many of us know far too well. We aren’t all inclined to make small changes, because we tend to want results, and we want them ASAP.

However, switching from a diet that includes large quantities of animal products to a diet that is heavily plant-based isn’t going to happen over-night. We know that sudden and extreme dietary changes are unsustainable, so instead of going from 0-100, focus on smaller, more attainable and achievable goals that you can start doing today and implement for life.

This might include incorporating a meat-free Monday into your routine, or substituting chicken with tofu in your favourite curry, or lentils instead of mince in a bolognese sauce. Stock your house with delicious plant-based snacks such as fresh fruit, vegetables sticks and dip, multi-grain crackers, home-made bliss balls/muffins/slices, and nuts and seeds so you have nutritious plant-based options at arms reach. Switching out your milk with plant-based options such as Inside Out’s Almond and Oat Milks, which are fortified with calcium, will still provide you with some of the macro and micronutrients you would find in dairy based milks.

Lastly, do keep in mind that plant-based diets don’t necessarily exclude animal products altogether. It’s important to always eat in a way that works best for you, your lifestyle and your health and nutrition goals.

What do you think is the biggest or most common myth you hear about plant-based diets?

That plant-based diets are the same as vegan diets. Despite what you may have heard, a plant-based diet is inherently different to a vegan diet. Vegan diets exclude animal products in their entirety, whereas a plant-based diet is a style of eating where plants form the basis of the diet but animal products aren’t necessarily omitted altogether.

Secondly, the idea that plant-based diets don’t provide you with all of the nutrition you need. This couldn’t be more untrue. Dietary patterns that are centred around the consumption of plants can easily provide all the nutrients you need to lead a healthy life. Despite common misconceptions, a well-planned, balanced plant based diet (one that includes small amounts of animal products or excludes them entirely) can be nutritionally complete, given you pay careful consideration to the nutrients present in the food groups you have limited or removed so you can replace these elsewhere in your diet from a food source that aligns with your dietary goals and values.