As of the early 21st century, it was estimated that 4 billion people live primarily on a<unk> , some by choice and some because of limits caused by shortages of crops, fresh water, and energy resources. In Europe, consumption of<unk><unk>  meat substitutes made up 40% of the world market in 2019 and was forecast to grow by 60% through 2025, due mainly to concerns for health, food security, and animal welfare. In the U.S. during 2019, the retail market for<unk><unk>  foods grew eight times faster than the general retail food market.
Plant-based diet
Feingold diet
Low-fiber/low-residue diet
Low-FODMAP diet
Stillman diet
Rice diet
Specific carbohydrate diet
Cotton ball diet