^ Luke, Kim. "Evidence That Human Ancestors Used Fire One Million Years Ago". Retrieved 27 October 2013. An international team led by the University of Toronto and Hebrew University has identified the earliest known evidence of the use of fire by human ancestors. Microscopic traces of wood ash, alongside animal bones and stone tools, were found in a layer dated to one million years ago
^ The sweetness multiplier "300 times" comes from subjective evaluations by a panel of test subjects Archived January 23, 2009, at the Wayback Machine tasting various dilutions compared to a standard dilution of sucrose. Sources referenced in this article say steviosides have up to 250 times the sweetness of sucrose, but others, including stevioside brands such as SweetLeaf, claim 300 times. 1/3 to 1/2 teaspoon (1.6–2.5 ml) of stevioside powder is claimed to have equivalent sweetening power to 1 cup (237 ml) of sugar.
Most food has always been obtained through agriculture. With increasing concern over both the methods and products of modern industrial agriculture, there has been a growing trend toward sustainable agricultural practices. This approach, partly fueled by consumer demand, encourages biodiversity, local self-reliance and organic farming methods. Major influences on food production include international organizations (e.g. the World Trade Organization and Common Agricultural Policy), national government policy (or law), and war.
^ Griswold, Max G.; Fullman, Nancy; Hawley, Caitlin; Arian, Nicholas; Zimsen, Stephanie R M.; Tymeson, Hayley D.; Venkateswaran, Vidhya; Tapp, Austin Douglas; Forouzanfar, Mohammad H.; Salama, Joseph S.; Abate, Kalkidan Hassen; Abate, Degu; Abay, Solomon M.; Abbafati, Cristiana; Abdulkader, Rizwan Suliankatchi; Abebe, Zegeye; Aboyans, Victor; Abrar, Mohammed Mehdi; Acharya, Pawan; Adetokunboh, Olatunji O.; Adhikari, Tara Ballav; Adsuar, Jose C.; Afarideh, Mohsen; Agardh, Emilie Elisabet; Agarwal, Gina; Aghayan, Sargis Aghasi; Agrawal, Sutapa; Ahmed, Muktar Beshir; Akibu, Mohammed; et al. (August 2018). "Alcohol use and burden for 195 countries and territories, 1990-2016: a systematic analysis for the Global Burden of Disease Study 2016". Lancet. 392 (10152): 1015–1035. doi:10.1016/S0140-6736(18)31310-2. PMC 6148333. PMID 30146330.
Most food has its origin in plants. Some food is obtained directly from plants; but even animals that are used as food sources are raised by feeding them food derived from plants. Cereal grain is a staple food that provides more food energy worldwide than any other type of crop. Corn (maize), wheat, and rice – in all of their varieties – account for 87% of all grain production worldwide. Most of the grain that is produced worldwide is fed to livestock.