Israel Smith developed depression after an enormous 2010 when he and his wife had grown their business rapidly and he ran a full marathon and published two books.
His wife Bel was heavily pregnant with their son, who was born in October.
"We kind of reached this point when my wife stepped out of the business and I'd been doing all this stuff and just pushing really hard, but not looking after my food and my diet," he told SBS Cantonese.
After a summer holiday break, Mr Smith said he "really couldn't get started again" and was "really not happy".
"I was staying up late watching rubbish TV, sleeping all through the day, disconnecting from my wife and my children - just generally feeling quite awful," he said.
Further, into the year, Mr Smith's GP and a psychologist both confirmed what the pair had suspected, that he was suffering from depression.
"I've learnt since then that it's actually very classic textbook postnatal depression which affects about one in 10 men when a baby arrives," he said.
How "cleaning up" the diet can help depression
While both his GP and psychologist agreed to prescribe him anti-depressants, they were also happy for him to investigate other options, since his depression was in an early stage and did not necessarily require the help of medication.
After digging around on the internet and reading through articles, Mrs Smith found an interesting connection between gluten sensitivities and mental health issues and had suggested her go gluten free and clean up his diet.
"So she did all the research on the recipes and the cooking and helped out in the family to make that transition. And so we went towards real-food, wholefood, that kind of stuff."
That includes lots more vegetables and fruits, as well as made-from-scratch meals that did not include gluten and sugar.
He recalled, "Within a few weeks, my body started to respond, and my brain started to clear. I feel like there's a fog lifting - I can see my way through now - rather than just having this big cloud of sadness and hopelessness hanging around all the time."
Mr Smith said it was interesting to see how speedily the change was and how much of the impact that had made.
"So the more we research into it, the more we realised that this is not uncommon that there's quite a link between how our gut behaves and how our brain behaves," he said.
"Things like inflammation in the gut which can be caused by eating things that your body doesn't agree with, [and that] can lead to the chemicals in your brain going out of balance."
The transition helped to improve the whole family's mental health as well.
"We decided that the whole family would change. And we noticed really quickly that our daughter started to improve her mood as well, as a result. [We thought,] wow, that was fascinating!" he said.
"She was a really quiet and anxious child - she bit her fingernails, she'd be very nervous, very moody and very volatile. She'd go from happy and peaceful to crying, screaming and running around the house, really quite suddenly. We couldn't figure out why."
Once the family altered their diet, his daughter became much more relaxed and calm and no longer showed the symptoms of anxiety.
Source: Flicker / Wendy Copley
Daughter "bullied" about lunchbox
Mr Smith said it's indeed often been referred to that mental health is a result of chemical imbalance, but there's often no conversation about the step before that - what causes the chemical imbalance.
"For my case, in particular, and in other cases through research, the chemical imbalance can come from poor diet, it can come from not giving your gut what it needs, or treating your gut so badly that it's constantly in a really reactive and toxic state."
As for his daughter, the pair prepared her lunchbox for the school began to change towards more real, whole food, homemade foods. But they realised her coming home shaking with hunger and not having eaten anything in her lunchbox.
"She said, 'I'm getting teased about what's in my lunchbox by the kids at school. The kids tell me that it looks yuk, and they say, we must be poor because we're eating no-packets food,' which is absurd," he recalled.
"So we ended up speaking to the teacher about it, as you'd do, because it was a bullying situation. And the teacher said, 'I absolutely agree with what you send to school with your daughter. I think her lunchbox was the best in the class, and I would love if every child ate like this'."
By that point, Mrs Smith had finished her health coaching qualification, when the class teacher invited them to visit the school and talk to the students about real food and what their daughter has to eat.
Mrs Smith then developed workshops for the children called "Mad Food Science", containing experiments that the kids could do to attract their interest into healthy food, such as trying a green smoothie, and some homemade snacks.
"They weren't told what was in them, and then when they went, 'Ah! This is so delicious!' Then she said, 'Right! Now let's tell you what's actually in this', and it was, for example, chocolate cake made out of beans rather than out of flour, he said.
Founding "The Root Cause"
The workshops were "ridiculously successful", which the pair was getting parents calling in to ask what Mr Smith and his wife had told their children.
"They couldn't believe that the children have come home and started going through the cupboard and pantry, reading all the packet labels, and telling mum and dad, 'We can't buy this anymore because it's too processed, it's got too many ingredients, and this food is not good for my body, so I don't want to eat that anymore'," he said.
"The parents were really happy about this but just couldn't understand what happened for them to suddenly shift."
Mr Smith said he and his wife then decided to explore a bit more on that and got invited back to work with the school as well as other schools in the area, delivering similar workshops to school children, growing by word-of-mouth.
"Our mission is to focus primarily on children's health and helping parents to make it easier for their kids to eat better foods, fruits and vegetables," he said.
"In most cases, what that looks like is, actually teaching the kids the same workshop as Mad Food Science, empowering the children to make better food choices for themselves. When they can be in the driver seat, they can take charge."
File. Source: Moodboard
