Yes it's true, there is a strong link between diet quality and mental health.
That is, if your diet consists mostly of junk foods, you're more likely to have anxiety and depression. Equally, if you don't have a junk food diet, but you also don't eat enough healthy foods, you're also more likely to have mental health issues.
So, what do we do? If our diet is poor and our bad habits feel concreted, where do we even start?
To get simple ways to promote mental health through diet and lifestyle (which everyone can implement), The Huffington Post Australia talked to three experts.
"What the research is showing is that people who make healthier food choices tend to have better mental health, and by that I mean lower rates of depression and anxiety. There is quite a clear link," Chloe McLeod, accredited practising dietitian and sports dietitian, told HuffPost Australia.
Many aspects of diets are important, and it all comes down to that very simple adage: Eat food. Not too much. Mostly plants.Felice Jacka
"Western dietary patterns that are characterised by high intakes of highly processed food, confectionery, refined carbohydrates and red meat are associated with poorer mental health," Natalie Parletta, accredited practising dietitian and senior research fellow investigating nutrition and mental health at the University of South Australia, told HuffPost Australia.
"While dietary patterns characterised by higher intakes of vegetables, fruit, legumes, nuts and fish are associated with better mental health outcomes."
"I think there still needs to be more research about specific nutrition causing those things, but definitely leaving out certain things or not eating enough of certain things can play a really big part in that," McLeod added.
Here are five ways to help promote mental health through your diet and lifestyle.
1. Follow a traditional Mediterranean-style diet
According to Felice Jacka -- associate professor, psychiatric epidemiologist and director of the Food and Mood Centre at Deakin University -- a key part of promoting mental health through diet is increasing intake of "healthful foods", which are the foods "we know sustain health".
"The brain is an organ and like any other organ in our body it needs nutrients from food for its development and to work properly," Parletta said. "The whole range of essential nutrients are required, such as the B vitamins, vitamins A, C, E, zinc, magnesium, selenium and more."
It's for this reason that Parletta and McLeod encourage people to follow a Mediterranean-style diet.
Vegetables are one of the most important ones when it comes to mental health.
"Foods that are high in nutrients, healthy fats such as monounsaturated fats and omega-3s, and polyphenols (which have antioxidant and anti-inflammatory properties) support good physical and mental health," Parletta said.
"This includes vegetables, fruit, nuts, seeds, legumes, fish and extra virgin olive oil -- much like a traditional Mediterranean-style diet."
"The Mediterranean style diet has some really great positive associations for promoting mental health factors," McLeod added.
2. Eat more vegetables
McLeod particularly recommends incorporating more vegetables into your diet.
"Vegetables are one of the most important ones when it comes to mental health," McLeod said.
"Only four percent of Australian Adults are eating enough vegetables on a daily basis. Even a couple of years ago that was eight percent. Even though there's so much more awareness around healthy eating and making healthy food choices, the fact that the number has dropped another four percent is crazy. It's something to definitely be concerned about."
To help promote mental and physical health, McLeod recommends to aim for the national standard of five-a-day.
"The actual quantity of food you can consume in a day if you're hitting that five serves of vegetables is way more than what you can consume if you're having, say, a bacon and egg McMuffin for breakfast, a burger at lunch and a pizza for dinner," McLeod said.
"If you're focusing on having a more plant-based diet, and getting at least five serves of veggies in per day, my feeling and experience is that you don't end up being as hungry in between meals, and you can be a lot more healthy in general because you're getting enough of the different micronutrients, polyphenols and antioxidants."
3. Cut back on junk food
It goes without saying that a high intake of junk food is not synonymous with long-term physical and mental health.
"Some of the other things to cut back on are the foods we already know aren't healthy for us," McLeod said.
"Cut back on things which are highly processed, high in refined sugars, high in saturated fat and lots of salt. If we're filling up on those things there's not enough space in our diet for these other healthy foods that our body requires.
"When you're filling up on those foods, you tend to feel more sluggish and lower in energy, and it makes it harder to get motivated to exercise."
However, this isn't to say you're never allowed to have that pizza or doughnut.
"I'm talking on a general, across-the-board basis. Having some of those treats is just as important for your mental health as not having them at all," McLeod said.
4. Exercise more
The link between mental health and exercise is really well established," McLeod said.
"If your diet is so poor that, as a result, you don't have enough energy to do any physical activity, it's not surprising that it's going to have negative outcomes on your mental health.
Try yoga, walking for 30 minutes five times a week, or participating in a team sport.
5. Get some sun
Although we often hide from the sun, McLeod said that one overlooked part of mental and physical health is vitamin D, which we get most effectively from the sun.
"Vitamin D is technically not really a vitamin, it behaves more like hormone in our body," McLeod said. "There's a lot of research now that's shown that low vitamin D levels are associated with a whole host of medical conditions -- everything from being more overweight to having mental health disorders, as well.
You may be read this and thinking, 'there's no way I have a vitamin D deficiency -- I live in Australia'. But one in four Australians are in fact vitamin D deficient.
"I know it sounds so silly because we live in Australia and it's beautiful and sunny, and the Cancer Council has done such a wonderful job of being really diligent with sunscreen -- and I'm not saying don't do that," McLeod said.
"But at the same time, if every time you're out in the sun and you're completely protected, that actually reduces the reaction of the sun with your skin, and the development of vitamin D."
To make sure you're getting enough vitamin D, spend some time in the sun each day.
"It's only 10 or 15 minutes a day. When you go out and get your morning coffee before 10am -- not at midday in the middle of summer -- you can walk 10 minutes there and back. You're getting extra exercise and you're also getting that sunshine.
"It doesn't have to be sitting there sunbaking and rubbing oil on yourself. It's not about that. It's about a short amount of time each day, and it definitely has great health benefits."
Click below to follow HuffPost Australia on Snapchat!