Now she has scrapped the meat and laughs at the idea of just three types of vegetables.

"When we get up in the morning it's smoothies: mango, berries, flaxseed, chia seed and spinach. By 9am the kids have had a full rainbow of food."

For the past year the Brewer household on Sydney's northern beaches has been vegan – that means mum Amanda, dad Trent, India, 9, Oscar, 4, and Noah, 2.

Even the three family dogs are served up specialty vegan dog food when it is locally available.

The Brewers are an example of the increasing move towards veganism in Australia, now the third-fastest growing vegan market in the world, after the United Arab Emirates and China.

Data from market researcher Euromonitor International has shown Australia's packaged vegan food market is currently worth almost $136 million, set to reach $215 million by 2020.

"An increasing number of companies are expanding their consumer appeal by staying away from animal ingredients whenever possible," said Ewa Hudson, head of health and wellness at Euromonitor International.

"The rising demand and trend for vegetarian and vegan proteins indicates where the market is moving right now."

Currently the biggest vegan food labelling market is the US ($1.75 billion), followed by Germany ($614 million), Britain ($507 million) and Australia.

In Australia the largest product sector for vegan labelling is dairy-type products, worth $83.7 million, followed by sauces, dressings and condiments ($26.3 million), biscuits and snack bars ($12.5 million), confectionary ($6.9 million), breakfast cereals ($5.4 million) and spreads ($1.1 million).

Alternative milk has experienced the strongest growth in recent years, driven by a strong shift towards almond milk and away from grain-based milk, such as soy.For the Brewer family, the switch to veganism happened gradually after Mrs Brewer researched and sampled the diet for six months.

She was largely drawn to the diet after the World Health Organisation released a landmark report denouncing bacon, hot dogs, sausages, ham, and other types of processed meat as Group 1 carcinogens, last year.

"We eat tonnes more fruit and vegetables ... and my belief system and my conscience are now in line with my actions, which I am able to pass on to my kids," she said.

After the morning smoothie, lunch for the children involves steamed vegetables, salad sandwiches and fruit for snacks.

Dinner could be a five-bean and tofu bolognese, vegetable soup, or homemade pizza, all made from the three vegetable boxes purchased at a local farmers' market every week for about $80, and a $200 shop at Aldi each fortnight.

Once a week the whole family uses an oral B12 spray, a vitamin which is usually obtained through animal products.

Nine-year-old India found the diet took some getting used to, having always eaten meat, eggs and dairy until she was eight years old.

"I like being vegan because it's good for the animals and the earth and it's healthy," she said, adding that she does not miss meat "at all".While some question the nutritional value of a vegan diet, dietitian and spokeswoman for the Dietitians Association of Australia Simone Austin said the diet can work.

"It can be balanced, as long as you plan well," she said, but added that people considering a vegan diet out of health concerns should not always assume it is more nutritious.

"Often people change because they think it's healthier. It's really important to realise it isn't necessarily healthier ... because people are not including foods they need."

Ms Austin said vegans needed to look harder for "protein, zinc, iron, omega 3s, calcium and B12" in their foods.

A recent study by the CSIRO and the University of Adelaide found one in six Australians is avoiding milk and dairy foods, despite having no medical reason to do so, prompting concerns of nutritional deficiencies.

Ms Austin said all vegans should seek fortified drinks and foods, such as soy drinks with added calcium.Switching the whole family to a vegan diet, Mrs Brewer said she faced mild opposition from family and friends, with some suggesting she was "brainwashing" her children.

"It was always those that had the least education about nutrition and had suffered the most medical issues," she said.

"When my kids are older and they are their own person they may make their own choices [to eat meat], and I will need to respect that."

Australian Dietary Guidelines say "appropriately planned vegetarian diets, including total vegetarian or vegan diets, are healthy and nutritionally adequate".