 Hi, I'm Sylvia. I'm an editor here at Food Unfolded. Today we will tackle a difficult question. Are vegetarian and vegan the most sustainable diets? It's challenging because many of us have our own strongly held beliefs around this topic and different actors in the food industry have a vested interest in the answers. It is clear that the reason to eliminate animal products from one's diet can be many. For example animal suffering or health. But we will try to compare the various diets only in terms of environmental, social and economic impacts. By and large vegetarian and vegan diets would really seem to be the most sustainable. The impact of animal products on the environment is much higher than that of land products. A few numbers make this clear. The production of meat, fish, eggs and dairy uses about 83% of world's agricultural land and almost 70% of the forested land is used for the production of feed and for livestock. Animal products also contribute to more than half of the greenhouse gas emissions of the entire food system. The scientific community is unanimous. Avoiding or at least reducing the consumption of meat and dairy products would bring great benefits for the environment. However, this doesn't mean that any vegetarian or vegan diet is automatically sustainable. Many plants products are actually responsible for very serious environmental and social damage. For example, from an environmental perspective, almond milk is often considered a more of a sustainable choice than cow's milk because it would allow us to cut on greenhouse gas emissions. But almonds are often grown in hot and dry climates and so they require huge amounts of water, fertilizers and pesticides to be produced. In other words, almond milk is more sustainable than cow's milk, but not the most sustainable alternative choice you could make. Then let's look at avocados. Europe imports them mainly from Peru, but also from Chile, Mexico, South Africa, Kenya and Israel. All countries with quite dry and hot climates. For this reason avocados require huge amounts of water to be produced. So much so that in regions like the Torca and Chile, the owners of some big plantations have been sold in legal pipes and wells to divert water from rivers and irrigate crops, taking away water from citizens and causing regional droughts. The Mexican cultivation of avocado is also often in the hands of local mafias who extort the income from farmers by keeping them to work in the fields under exploitative conditions. The situation around avocado is so controversial that it was suggested it could become a new conflict commodity. But we don't even need to go too far to find serious social and economic issues. In many European countries we could be buying cheap fresh fruits and vegetables, such as tomatoes, sometimes harvested by exploited laborers, who are kept in a state of legal, social and economic invisibility. So buying sustainably is less straightforward than we might think. This means that even those who have already removed animal products from their diets should still try to consider these other factors when buying products. For example, we could buy food labeled fair trade, which means it was produced in an ethical way respecting the rights of workers. But what to do if we don't want or cannot yet remove animal products from our diet? Several studies have shown that a flexitarian, meaning a semi-vegetarian, flexible approach could help us reduce our environmental and social impact, as well as combat waste. This could be in buying meat or fish occasionally and only when they're close to their expiration date. Or buying those usually discarded parts, such as tongue or labor. This approach would allow us not to waste food that was produced at a great cost for the environment, but also to use our purchasing power to discourage its production. A study published in Science in 2018 suggested that if we halved our meat consumption and we only bought from low environmental impact producers, our effort could achieve up to 70% of the ecological results of a vegan diet. But all things considered, if our goal is to follow a more sustainable diet that respects people and ecosystems, then reducing our consumption of animal products is a fundamental step to take.