Nutrition (latin nutrire: food) can cover both directions, depending on whether one is interested specifically the physiological mechanisms of cellular metabolism, or more generally to the provision of food to the body as a whole.
Physiology and Metabolism
The functions of nutrition are one of the major functions of physiology.
Nutrition means all phenomena that provide nutrients to cells and export of waste metabolism. It thus encompasses all physiological functions necessary to use (metabolism) of nutrients for growth, maintenance, operation of the organization, and to produce heat and energy:
* Absorption of food
* Assimilation and food processing: digestion, assimilation root (see Plant Nutrition), photosynthesis
* The movement of indoor environments (blood: see bloodstream, sap)
* Respiration (provision and export of gas to the external environment cells)
the energy value is: 1 kcal (kilocalorie) = 4.18 kJ (kilojoule)
Nutrition is defined here as the science that analyzes the relationship between food and health: study the composition of foods, their properties and their use by the body. These studies lead to the diet. It also takes into account the context of nutrition, eating habits of individuals, particularly during meals or snacks.
However, from clinical observation of diseases whose origin was a lack food (for example, scurvy), nutrition today also diseases such as cardiovascular problems and cancer (with the method Kousmine for example), osteoporosis and hypertension (excess salt in particular), type 2 diabetes, obesity, autoimmune diseases, Alzheimer's disease.
Nutrition plays an essential role in preventing many diseases. For example, more than 100 000 cases of cancer could be avoided in France each year by simply changing eating habits.
It should also be recalled that the nutritional status is a prognostic factor in the development of cancers. A person in power will be more at risk of complications that a person receiving food conforming to the needs of the organization.
The complex process which nutrients are submitted - interactions between food, environmental degradation, energy transformation and release of this energy, transport and use of chemical compounds for construction (anabolism = construction; catabolism = waste management) and specialized tissues maintaining good overall health - are only partly clarified. Choices significant nutritional must be made to ensure the good health of individuals, such as very young children and the elderly, and entire populations who suffer from malnutrition.
The adaptation of feeding practices to the satisfaction of physiological needs is the diet.
Read also Vitamin K