The "hamburger wars" reached Australia this month with upmarket local hamburger chain, Grill'd, declaring a meatless Monday on April 15.
Grill'd has 136 locations nationally, mainly in the major cities, and was founded in 2004 in Melbourne by Simon Crowe.
His decision to only offer plant-based hamburger "patties" - imported from Beyond Meat in the US - for one day was widely applauded on social media but also panned.
Critics queried why the trendy fast-food chain whose success has been built on grassfed beef and lamb and RSPCA-approved chicken would risk alienating its core loyal customers by restricting its menu to vegan burgers only.
Mr Crowe said Grill'd, which has only recently introduced vegan burgers, planned to have half its menu plant-based by 2020.
The plant-based patties are being supplied by Beyond Meat, a Los Angeles-based company whose high-flying backers include Bill Gates, founder of Microsoft.
Its products are now available in 25,000 restaurants, hotels and universities worldwide.
Beyond Meat one of the leaders in the new meat-substitutes "frontier" which is spreading at a rapid rate, particularly in hamburger chains.
Burger King in the US is now selling a new Whopper beefless burger in partnership with the start-up company, Impossible Foods, which is supplying patties made with heme, a protein cultivated from soybean roots that mimics the texture of meat.
Burger King will trial the Impossible Burger in 59 restaurants around St. Louis and, depending on the response, will make it available in its 7200 outlets across America.
Burger King's Australian subsidiary, Hungry Jack's, launched a vegan cheeseburger late last year.
Fast-food giant, McDonald's, is now trialling a McVeggie burger in some South Australian stores and is under pressure to launch a range of plant-based burger options in its network American outlets.
Those who are pushing to develop plant-based products that mimic meat are driven on a number of fronts, notably to tackle concerns about the alleged impact of livestock farming on the environment or human health, or both.
They are aiming their products at meat eaters rather than vegans and vegetarians, particularly the "flexitarians" who sporadically eat vegan.
"Flexitarians" are typically millennials who are curious about new plant-based meat alternatives, are seeking new dining experiences and are also worried about the impact of animal-based agriculture on climate change.
Producers of plant-based "meats" are constantly upgrading their products to grab a share of a growing market.
Impossible Foods has recently unveiled the Impossible Burger 2.0, a revamped gluten-free version of its original patty with wheat replaced by soy along with sunflower and coconut oils and heme, an iron-containing molecule that gives beef its flavor.
Beyond Meat has also launched Beyond Burger 2.0, a gluten-free patty blending pea, mung bean and rice protein, along with coconut oil, potato starch and beets for color that's intended to be more fibrous and chewy.
Meanwhile farmers around the globe are continuing to demand that plant-based meat alternatives along with lab-grown meat not be labelled with traditional meat names such as hamburger and sausage - and they are having some major wins.
Missouri was the first state in the US to prohibit the term "meat" in vegan and other plant-based substitutes but its laws are being challenged by makers of plant-derived foods.
Mississippi and South Dakota have adopted similar laws with Montana close to joining them. Arizona, Arkansas, Colorado, Illinois, Indiana, Nebraska, North Dakota, Virginia, Washington and Wyoming are considering following suit.
And members of the European Parliament's agriculture committee have just voted for a new law to ban the use of words such as "burger", "hamburger", "steak", "escalope" or "sausage" on food packaging, promotion or marketing if the food concerned is "primarily made up of proteins of vegetable origin".
The proposed rule, which is not yet EU law, is in line with previous rules governing the dairy sector, that vegan dairy alternatives made from soy or tofu must not call be called "milk" or "butter".
The "veggie disc" has emerged as one possible new name for plant-based burgers.