Diet literally means lifestyle.
The diet should not be considered as a restrictive diet but, on the contrary, an optimal nutritionally dietary intake, which allows better use of foods in pathological or physiological conditions.
Proper nutrition must take account of a number of individual data and generics to determine the composition of meals: the knowledge of the individual energy requirements, the allocation and the rhythms of nutrient intake, the food choice according to their content of nutrients and individual needs, cooking systems.
A balanced diet is a diet in which nutrients are present in sufficient quantities to satisfy, without exceeding, body's energy needs, intake of substances intended for the renewal of tissues and those having regulatory and protective function.
To build a proper diet you should have to know the needs of the individual which is addressed, to know the characteristics of various foods and identify the quantity and quality of foods needed to meet your specific needs. It is therefore necessary to proceed through certain stages generically applicable to adults. Teenagers and pathological conditions require further studies because the individual metabolic characteristics in growing age and during particular conditions have specific requirements and variability.
The building of a balanced diet is divided into the following phases: definition of ideal weight referring at the weight intervals recommended in relation to height, body size and age;
daily calorie requirement definition as the sum of the basal metabolism and energy requirements due to physical activity;
nutrients requirement definition;
choice of foods to be included in the diet, taking into account the chemical composition, degree of assimilation and undergoing modifications due to cooking;
distribution of food in an adequate number of meals or rations.