But their reaction to the "planetary health diet" was more a matter of "do not tell me what to do" than consider how our grandchildren and great-grandchildren will survive on a crowded planet.
The rise of veganism is related to concern for the future. The large increase in the number of people who signed up for the global event, Veganuary this year, from 3300 participants in 2014 to 225,000, was attributed to sustainability concerns.
Cruelty Free Shop director Jessica Bailey says the demand for vegan food in Australia has grown exponentially last year.
"In addition to a huge increase in sales, we saw a large increase in new vegans entering our stores," she says.
"Many fad diets come and go, like paleo and keto, but veganism is different because it's not a diet, it's an ethical lifestyle choice and that means it will continue to grow."
For some Veganuary participants, it was a short-lived experiment, ending with a plate of bacon and eggs before the start of Febfast, but my herbivorous journey will continue for the rest of 2019.
Like many baby boomers I know of, I am concerned about overfishing, industrial stock-breeding, land management, water scarcity, food security, biodiversity loss, deforestation, pollution, and waste disposal.
Being vegan gives me a chance to examine problems from the inside out. I want to know what it's like to just survive with plants and see how my body changes.
The blood tests I did before Christmas show that I am a picture of health, thanks to a flexible diet. But can I sustain this on a vegan diet?
Nutritionist Nicole Dynan assures me that the Australian Dietary Guidelines, based on a review of 55,000 studies, state that "properly planned vegetarian diets, including vegetarian diets or whole vegans, are healthy and nutritionally adequate."
"A purely vegetable-based diet can be balanced if well planned, but it should not be assumed that it is automatically healthier," says Dynan.
"Those who avoid meat need to work hard to ensure that" nutrients at risk "such as protein, zinc, iron, omega 3, calcium and vitamin B12 are in their food."
"Choosing fortified foods and beverages, such as calcium-added soy beverages, can help." But, as Bailey points out, veganism is more of an ethical lifestyle than a diet.
A purely vegetable based diet can be balanced if well planned, but it should not be assumed that it is automatically healthier.
I plan to spend my vegan year examining relevant studies and talking to scientists, economists, nutritionists and other experts about how veganism can contribute to saving the planet.
I started by asking the human evolutionary biologist Tanya Smith if there was evidence that humans could evolve to become herbivores?
The author of The teeth of the tales tell According to dental enamel studies, the diets of early hominins were varied and included meat. "Homininos, our ancestors, evolved in diverse environments and spread to other environments," she says.
"They have adapted to local conditions and resources available."
Smith, of the Australian Center for Human Evolution Research at Griffith University, says hunter / gatherer groups were opportunistic and seasonal eaters.
"I do not find it difficult to imagine that we went through brief periods of reliance entirely on vegetable-based food, but this was complemented by other periods when meat and fish were available," she says.
Brisbane-based nutritionist Lulu Cook, founder of the Gut Feeling Nutrition + Therapy website, says it is unlikely that people can evolve to process vitamin B12 just from plants or no longer need vitamin B12.
"Studies conducted over many years have shown that not getting B12 from animal-based foods, dairy products or supplements carries a risk of cognitive decline and dementia," she says.
"Fertility is also hampered by vitamin B12 deficiency. For the population to evolve, we must reproduce successfully and transmit any new gene expression. " These ideas can reinforce the view that we need meat to survive.
But those of us who have food security and access to supplements can still choose a plant-based diet, especially if that contributes to sustainability.
My impact as a vegan individual may be minuscule, but as part of a consumer revolution, I can help conserve the environment for future generations.