The United Nations (alongside many other studies) has identified vegetarianism as one of the major ways to reduce impact on the planet; it has also concluded that a global shift towards a vegetarian or vegan diet is necessary to combat the worst effects of climate change. Also, Biosphere Expeditions is all about animal conservation, research and caring for animals in its broadest sense. Because of all this, no animal meat (including fish) that is connected with animal abuse or suffering or obtained using unethical or unsustainable production and harvesting methods is served on our expeditions. And this is true for the vast majority of meat, especially in the countries we work in.

On ethical grounds, there are very obvious animal welfare, sustainability and environmental impact issues around meat production, especially in many of the places we run expeditions to, so apart from the huge environmental impact of meat, this is another reason for our veggie expeditions. According to a United Nations statistic, raising cattle for beef and milk, for example, spews more greenhouse gases into the air than all of the cars currently on the road. The same UN report also found that the livestock industry wreaks havoc on our land and water - taking up vast amounts of scarce resources and polluting the waterways more than any other industry.

And further on ethics, it's tough to think about how your steak or pork chop was made. According to the United States Department of Agriculture, 9 billion cows, chickens, turkeys, ducks, pigs, and sheep are slaughtered for food annually in the USA alone. And these animals often suffer greatly in tiny cages, crates and pens, before enduring cruel slaughter practices. And this is in the USA. I am loathe to think about the meat and fish production processes in many of the countries we work in. The Humane Society of the United States estimates that if every American cut out meat just once a week, about 1.4 billion animals could be spared each year.

We hear this quite a bit. We make lots of choices for people on our expeditions: Where they stay, what time they get up, what model of car they drive, the type of equipment they use, the activities they do and how, etc. The food they eat is simply another one. Their choice is to accept our ethics and philosophy and come with us, or not, because they don't agree with our policy or because they don't want to do without meat for a week or two. There are a million ways to spend your holiday, including working in conservation. And as far as I am aware we are the only citizen science organisation with a vegetarian policy, so if people feel they really can’t do without meat for a week or two, then of course it’s their choice to do something else.

[Laughs]. Yes, Napoleon said “c'est la soupe qui fait le soldat”. And of course that’s true, so we try hard to provide our teams with the best locally produced food we can, just without the meat. After all we are a conservation organisation concerned with animals, so it really makes no sense for us to care and do something about the decline in biodiversity and then contribute to the problem by tucking into a piece of meat or fish in the evening. Research has shown that industrial meat and fish production is also a major cause for the loss of biodiversity. There may be fish that are taken sustainably and obviously the locals are all bound to eat fish & meat, but we want to set an example (even though it may not be understood by many or even most) and err on the side of caution, reducing our impact as much as we can.

It is a myth that a vegetarian diet does not have enough protein or provide enough energy. After all there are many vegetarian or vegan Olympic athletes as living proof. Not only will you get all the protein you need, but you won't suffer from an excess of it. Ample amounts of protein are present in whole, natural plant-based foods. For example, spinach is 51% protein; mushrooms 35%; beans 26%; oatmeal 16%; whole wheat pasta 15%; corn 12%; and potatoes 11%. Plant proteins are as complete as complete can be. The myth that they're not, or are of a lesser quality than animal proteins, dates back to experiments performed on rats in the early 1900s. The meat, dairy and egg industries have marketed the hell out of this ancient research and even in this day and age the majority of people still think the only way to get complete protein or enough energy is through meat. This is simply nonsense with no basis in scientific fact. Also, the silly focus on protein – modern diets are anything but protein-deficient – distracts attention from the high-fat and saturated content of meat. To meet nutritional requirements, you only need to eat about half a gram of protein for every pound you weigh. Even if you are a vegan and eat no animal products at all, you almost certainly get enough protein from the grains, beans and vegetables that you eat.

In addition, your energy levels will actually be more constant and consistent on a vegetarian diet. Think of high-fiber and nutrient-heavy plant foods as the big logs in the fireplace that burn for hours. Think of low-fiber and nutrient-light foods such as simple carbohydrates as wads of newspaper that go up in a flash. On a vegetarian diet, you are less likely to have the meat-based energy peaks and troughs. And if people are tired on expedition, then I think this is because of the hard, physically and mentally demanding work they are doing, rather than the food we are serving.

There are lots and lots of studies that have shown the health benefits of a vegetarian diet. A study by the American Heart Association and University of Vermont has shown that your risk of the number one killer of people, i.e. cardio-vascular disease and heart attack, lowers significantly with a vegetarian diet.

There is also an increasingly clear link between the number two killer - cancer - and meat. In one study of more than 35,000 women published in the British Journal of Cancer, those who ate the most red and processed meat were found to have the highest risk of breast cancer. Other research has linked meat consumption to colon, prostate, pancreatic and gastric cancers as well. One theory, according to non-profit group The Cancer Project, is that foods with high levels of fat artificially boost the hormones that promote cancer.

And further on health issues, subbing a veggie burger for a hamburger is a no-brainer way to save a lot of calories. But the meat-weight relationship goes beyond calorie maths. A study by Imperial College London found that those who ate about 250 g of red meat, poultry, or processed meat a day (the size of one half-pound steak) gained more weight over five years, than those who ate less meat, even if they consumed the same amount of calories overall.

Good one [laughs]! First of all, we are not a profit-driven business. We are a non-profit conservation charity. So it’s not about bums on seats and maximising profits. It’s about bringing people together to achieve things in wildlife conservation in a way that is as ethical and low in impact as possible. It’s about putting our mouths where our hearts are, about being concerned with conservation and the environment on all possible levels during the expedition. So what we ask people for is their cooperation and understanding for a week or two, which brings us back to choice. Of course people do have a choice whether to come with us on expedition and share in our philosophy and ethics for a week or two. It’s clear what we stand for - and if you don’t stand for things, you fall down easily.