A BALANCED DIET. NUTRITIONAL REQUIREMENTS
All the substances we ingest, whether for nutritional purposes or not, with the exception of medicines, make up our diet. The diet characteristics vary according to the individuals, their race, customs, religion and times of the year.
A balanced diet should help the individual, taking into account his or her age and special situations such as pregnancy or growth, etc., maintain an adequate state of health with optimal capacity to perform the physical exercise his or her job might require.
A balanced diet must meet the daily essential nutrients (vitamins, amino acids, minerals and fatty acids) and energy requirements, with no excessive intake of any of the nutrients. Because no food is capable of providing the adequate amount of all nutrients, a dietary balance is obtained by combining the different types of foods.
There is no universal balanced diet. A diet must be adjusted to the individual's needs (age, sex, and anthropometrics), availability of foods where the individual resides, personal likes and dislikes, religious believes, etc. In general terms, a balanced diet should meet the following requirements::
Besides these nutritional criteria, one should not forget that a diet should be pleasant, varied and acceptable for the subjects for whim it is intended.
Nutritional requirements are the amounts of each nutrient needed by the individual, considering the quality and quantity of each of these nutrients in particular. The nutritional requirements refer to the specific individual.
Recommended daily intake or recommended daily allowances (RDA) for a given nutrient refers to food groups and are defined as the reference values for the intake of essential and energy nutrients to main the individual in an optima state of health. The most widely known RDAs are those established by the Food and Nutrition Board in the United States. However, RDAs specific for the European Union (Reference Nutrient Intakes for the European Community) were issued in 1993. This organisation defines the so-called "average requirement" (AR) and the minimal requirement (Lowest threshold intake or LTI). LTI is defined as the intake of nutrients below which all individuals will develop a deficiency of the said nutrient so as to differentiate LTI from the RDA.