Eat lower on the food chain and shrink your carbon and water footprints by making mushrooms a staple in your home. Unlike raising animals for meat which pollutes the environment and requires inordinate amounts of space, water, antibiotics, and animal feed (usually made of grain and other crops that also need to be grown), mushroom growing uses discarded organic materials for substrate. Unlike most agricultural crops that also require inordinate amounts of space, water, fuel, fertilizers, and pesticide (potent greenhouse gases!) to grow, mushrooms can be grown vertically, in low-light conditions, and require minimal water and effort.
While the mushroom fruiting bag is made of polyethylene plastic (huhu), mushrooms are still a less wasteful food option compared to other food types, which not only take a lot of resources to raise/grow, but also a lot of resources to pack, transport, and store. You see, fertilizers, pesticides, antibiotics, animal feed all usually come in plastic, too.
Growing your own mushrooms is also more cost effective than buying from the supermarket. Grocery mushrooms come in polystyrene and plastic packaging, and are still also grown in similar polyethylene plastic fruiting bags at mushroom farms. Why not cut out the middleman and grow your own?
While you won't survive on mushrooms alone (because you need calories), mushrooms have a great deal of nutritional value, are full of micronutrients, and are considered a superfood.