''The second principle is get rid of processed, packaged muck that's masquerading as food. So anything that's in a box or a container with a use-by date and it doesn't matter what graffiti is written on the box like 'low fat' or 'no cholesterol', it's typically not good for you.
''Anything from a bakery with pastry on the outside of it is also not good for you. So it's not the meat in meat pies that's killing you, because there's no meat in a meat pie, it's the pastry on the outside. And all these things are full of trans-fats.
''Takeaway food is poison, of course. White death, to me, is sugar, salt, white bread, rice, pasta and potato. These things go straight to the belly and cause significant abdominal obesity.''
Instead, eat three to five serves of vegetables a day. ''A serving is about half a carrot so we're not talking about a huge amount of food. Couple of pieces of fruit a day, but even too much fruit has natural sugars in it and can still contribute to abdominal obesity. I think you should only eat two pieces of wholegrain bread a day. And little bits of meat, fish, dairy, eggs, nuts, olive oil and grains and that's about it. There's your diet.''
Got it? The Sydney medico, who will speak at the Mulloon seminar, is well versed in putting out his message, the author of seven books, with reglar television and radio appearances. His book, Five Stages of Health ''debunks the myths and hype of modern health'', leading to his other big belief - that prevention is better than cure.
''Orthodox doctors, of which I am one, I think, focus too much on that wonderful saying, 'If all you have is a hammer, everything looks like a nail.' And the hammer that we have is the script pad or scalpel. We tend to gloss over the importance of lifestyle modification,'' he says. ''The people who practise good lifestyle principles reduce their risk for all significant diseases by somewhere between 60 and 70 per cent, whereas a drug that reduces your cholesterol might reduce your risk of a heart attack by 20 or 30 per cent, with a potential for a bucket of side effects. So lifestyle principles across the board are much more powerful than anything a doctor can do for you.''
When Walker was in his 20s studying cardiology, he ''just thought it was bizarre that the significantly obese person or the smoker would be coming back for their second lot of bypass surgery. I thought there's got to be a better answer to this.''
That's not to say he doesn't prescribe drugs or send patients to surgery. ''But I also say to them, the acute treatment, the chronic treatment, is changing your attitude to yourself and doing something about that,'' he says.
''I've got two distinct groups of patients. I've got those who follow the advice I give them and they become long-term mates of mine and I see them once a year to ensure they're maintaining the healthy practices and maintaining their medication. And then I've got those who don't follow my advice and whittle away bits of their heart and suffer a premature death.''
Walker's top five principles for healthy living:
1. Get down your belly fat.
2. No addictions. You cannot be healthy if you smoke, if you drink too much alcohol. You cannot be healthy if you snort cocaine.
3. Good quality eating and less of it.
4. Have a regular habit of three to five hours a week of some form of testing exercise - exercise that makes you a bit hot and short of breath. So going for a stroll is not good enough.
5. The best drug on the planet is happiness, peace and contentment.
''Life isn't about making some big decision to be healthy,'' he said. ''Life is about making 30, 40, 50 small instantaneous decisions every day like 'I won't eat that biscuit', 'I won't have that extra glass of wine', 'I'll walk up the stairs instead of take the escalators', 'I won't yell at that fool who just cut across the front of me in the traffic'. Those are the decisions that really take us towards better health.''
The link between diet and disease is of particular interest to Peter Gibbs. When called on to diagnose a sick animal, this veterinarian looks first to diet. And he says this is a practice others in medicine can learn from - and the message he will bring to the Mulloon seminar.
''We as practitioners need to look more totally at what people have done and not just whack them on medicine,''
he says. ''Maybe there are alternatives: changing their diet, changing their vitamin and mineral intake and balancing their life that way.''
In animals, Gibbs has observed a kind of innate, instinctive intelligence about what they eat. For instance, he has seen sheep avoiding crops that are high in nitrate because this substance can cause blood oxygen problems. ''They won't eat things that are poisonous to them unless they have to.''
Likewise, he finds animals can be counted on to choose foods to counteract deficiencies. ''You'll see horses and cattle, if they don't have enough fibre in their diet they'll go eating bark off trees. In a paddock if you've got cattle or sheep and you put out a bale of hay and they really get stuck into that bale of hay you know they really need roughage.''
He believes humans have lost the instinctive ability to select the right sorts of foods for themselves. For him, diagnosis could take the form of simply looking around a landscape: dandelions could cause nerve damage in horses, a particular clover could bring about weak muscles in lambs, a lack of selenium could give cattle reproductive problems.
Microbiologist and immunologist Dr James Chin believes diet can play a role in improving the outlook for children with autistic spectrum disorders.
He suggests, for instance, the importance of folate. This is a B-group vitamin essential for healthy fetal development and preventing defects such as spina bifida if taken before conception and during pregnancy. However, Chin proposes that mothers continue to take the supplement after they give birth, so the baby doesn't suffer a sudden deprivation, saying it could help in tackling autistic spectrum disorders.
Chin also recommends amino acid supplementation, such as tryptophan. Amino acids play an important role in shaping the ability of individuals to express feelings or moods.
''One of the principal problems associated with autistic spectrum disorders is speech and coordination. They have problems with cognitive functionality. So they can't look you in the eye, they tend to be easily distracted, they tend to have a lot of irritable movement. And that is because the neurons in the brain are not firing and connecting in the right order,'' he says.
The best sources of tryptophan are foods such as oats, bananas, dates, milk, cottage cheese, meat, fish, turkey, and peanuts, according to vitamins and health supplements guides.
Chin says in the past year he has seen six mothers who have given their autistic spectrum children amino acid supplementation and found ''significant improvement in stabilising the temperament of the children. They become less irritable and can you look you in the eye. This is after only a small period of two weeks.''
''Nutrition is something most GPs don't pay too much attention to, especially with ASD kids. We found nutrition really helps. Then, of course, antioxidants also play a very important role because the brain has a constant build-up of toxins.''
Chin also points to work recently shown on the ABC's Four Corners program examining the possible links between harmful bacteria in a child's gut and ASD.
Chin, who has done extensive research in gut health, believes supplements of probiotics can help.
with Claire Low and Megan Doherty. Are You What You Eat? is on October 6, dinner starts at 5.30pm, $130, themullooninstitute.org/courses-e vents/food-the-art-of-health