Nutrition is the biochemical and physiological process by which an organism obtains and uses food to sustain its life. It provides organisms with the necessary nutrients to create energy and chemical structures. Without sufficient nutrients, malnutrition can occur. Nutritional science is the study of nutrition, usually focusing on human nutrition.
The process of obtaining food is known as nutrition. Specialty pet foods have been manufactured since 1860, and subsequent research and development has addressed the nutritional needs of pets. Good nutrition is essential for biological life to maintain its ability to repair, grow, and function. Nutrient deficiencies, known as malnutrition, occur when an organism does not have the necessary nutrients it needs. Most cultures add herbs and spices to foods before eating them to add flavor, although most do not significantly affect nutrition. Grain cultivation and bread production have been a key component of human nutrition since the beginning of agriculture.
Prokaryotes, including bacteria and archaea, vary greatly in the way they obtain nutrients in all nutritional groups. Early human nutrition consisted of seeking nutrients similar to those of other animals, but it diverged at the beginning of the Holocene with the Neolithic Revolution, in which humans developed agriculture to produce food. The first vitamin to be chemically identified was thiamine in 1926, and the role of vitamins in nutrition was studied in the following decades. Nutritious foods are foods that are especially dense in one or more needed nutrients, such as eggs, fish, liver, avocado, green vegetables, beans, and legumes. Chemists in the 18th and 19th centuries experimented with different elements and food sources to develop theories about nutrition. In domestic animals, such as pets, livestock and working animals, as well as other animals in captivity, humans manage nutrition through animal feed. For humans, good nutrition is extremely important for cell function, tissue repair, metabolism, immune competence, cognitive function, physical activity, maintenance of internal homeostasis, and overall health.
Nutrition is defined as the processes by which living organisms obtain and use these acquired nutrients to maintain biological life. Plants need very considerable amounts of water for nutrition and growth; therefore, water retention capacity is important.