One of the biggest criticisms in the increasingly polarized vegans versus meat debate is the impact and provenance of some meat or dairy alternatives.

How can a lifestyle built on ethics and morals justify swapping locally-sourced sustainable meat for processed food that might contain soy from rainforest areas, palm oil, and other problematic ingredients? So the argument goes.

A lot of the hype has focused on the huge raft of new vegan products often processed food made to replicate meat using a variety of extracted ingredients. But not all vegans choose to base their diet on such products.

Maresa Bossano, a vegan of 27 years who runs the Love Food social platforms for ethical vegans, says: In terms of vegan food, I eat nearly 100 per cent organic and I buy local fruit and vegetables direct from farmers whenever possible. I also try to buy UK-grown produce for other foods like grains, pulses, nuts, etc. although this is harder, as we don't produce a lot in this country.

Of course, I eat imported foods, but I try to mainly get European-grown fruit when it's in season. I do eat things like pineapples and avocados but consider them a luxury not something I eat every day. What I would never do is buy blackberries grown in Mexico in a plastic punnet. I believe in eating seasonally and the rest of time doing without.

Many vegan foods imitate meat using a range of different ingredients.

Bossano says she isnt against meat alternatives per se but would never eat something that is ultra-processed and has lot of ingredients that I don't recognise.

In terms of its environmental impact, buying highly processed, over packaged foods using ingredients like palm oil or GM soya is causing a lot of damage to wildlife and wiping out species like orangutans, she says.

There is an assumption, leading to accusations of hypocrisy, that vegans should care about all aspects of sustainability, but that isnt actually part of the core veganism principles.

From a vegan perspective, the only ethics this lifestyle is concerned with is animal rights, says Dominika Piasecka of The Vegan Society.

While many vegans of course extend these to include planetary and human health, at its core veganism is simply about avoiding the use and abuse of non-human animals.

And while sustainability and veganism are closely related, they are separate issues, she says, adding that a plant based diet in itself has been shown time and time again to be the best off-the-shelf diet for our planet.

Its a point that inevitably does spark discussion, as many of the plant-based ingredients in a vegan diet, soya being the obvious example, arguably do have an impact on animal welfare via habitat loss in producer countries, as well as other environmental impacts.

Fruit, veg and pulses can be used as protein alternatives in nutritious meals.

Personally, I think all vegans (and non vegans) should be concerned about sustainability, as anything that harms the environment is inevitably harming wild animals, says Bossano.

Industrial agriculture is responsible for destroying the habitats that wild animals rely on to survive, both in tropical rainforests and in the UK.

It also relies on chemical pesticides and fertilisers which are damaging to insects, birds and other wildlife and which can pollute aquatic habitats. Whereas small scale organic farming enhances wildlife by providing food and homes for butterflies, birds and bees, and building soil fertility.

While leading scientists behind the IPCC report on climate recommended reducing intake of intensively-produced meat as part of a balanced, sustainable diet, the picture about simply switching to plants regardless of impact is more nuanced.

Food miles, fairly traded food, GM ingredients, pesticide use and transparency are all relevant and vital in a wider discussion about food sustainability: the difference being, according to The Vegan Society, veganism is not aiming to solve the whole picture.

Veganism isnt concerned with these issues. While they are of course very important, they are the extra step people can take after becoming vegan, says Piasecka. Our first priority when working with new vegans is that they understand the ethical reasons behind this lifestyle choice and that they are aware how to balance their diet properly.

For Bob Andrew, development chef at organic veg box company Riverford, the mainstream interest in veganism risks continuing the trend for convenience food, to the detriment of scratch cooking with fresh fruit and vegetables.

Black garlic works as a vegan stock cube.

The rush to fill the shelves with new vegan products is in danger of repeating the worst aspects of the wider convenience food market, by touting an equally unbalanced diet replacing one high protein, high fat, and high salt product with another, often with a lack of transparency over ingredients and potentially higher air miles, he says.

It is all about balance. Use it as a chance to bring a wider variety of veg into your diet and try cooking with more legumes, pulses and nuts to provide protein. If you do buy processed foods, remember, the fewer and more recognisable ingredients the better.

Andrew sees Veganuary as a perfect opportunity to discard old vegetable prejudices and learn new techniques, such as fermenting, roasting or slow-cooking, instead of the age-old boiling or steaming.

While the official stance sees veganism and sustainability as separate issues, when it comes to food, nuance and complexity are more representative of everyday lives and values.

With that in mind, provenance, recognising ingredients and conscious shopping decisions can all help create a sustainable Veganuary.

Chef Bobs sustainable Veganuary shopping list:

Mushrooms. Texturally, mushrooms are an easy way to ape a meat-like bite, without resorting to soya or seitan, a meat substitute made of hydrated gluten.

Sweet potatoes. They sit somewhere between a potato and squash, so use them as a proxy for both with abandon. Bake in their jackets, slice in a gratin or cleave into wedges and roast. They make for a smooth velvety mash, silken soups or an ideal backbone for any number of curries or stews.

Brassicas. Learn to eat your greens! And do it without boiling everything into slimy submission. Your sprouts, broccoli, cauliflower and even kale can be oven roasted to great effect the florets catch at the edge, making for a deeper flavour and texture.

Chickpeas. Think beyond hummus you can blitz them into falafels, braise into stews or cook down into a mash as a simple side to a veg-heavy dish. You can even use the water from the tin (resplendently named aquafaba) to use as an egg substitute in baking. As an alternative, try British-grown fava beans or carlin peas to support British farmers and cut food miles.

Black garlic. Think of them as the ultimate vegan stock cube but without all the emulsifiers and maltodextrin. Simply pop a few cloves into soups or stews to add complexity and depth.

More here:

How to be a 'sustainable' vegan - Wicked Leeks