Plant-based diet
A plant-based diet is a diet of any animal (including humans) based on foods derived from plants, including vegetables, whole grains, legumes and fruits, but with few or no animal products. The use of the phrase has changed over time, and examples can be found of the phrase "plant-based diet" being used to refer to vegan diets, which contain no food from animal sources, to vegetarian diets which include eggs and dairy but no meat, and to diets with varying amounts of animal-based foods, such as semi-vegetarian diets which contain small amounts of meat.
Plant-based diets have been noted to offer certain health benefits to humans, whether they are entirely plant-based and free of animal-based foods, or contain limited amounts of them.
Many people who live on a plant-based diet are thought to do so out of economic necessity. As of 1999 it was estimated that "an estimated 4 billion people live primarily on a plant-based diet", and that "shortage of cropland, freshwater, and energy resources requires that most of the 4 billion people live primarily on a plant-based diet".