In order to achieve the specific nutritional objectives of an individual, individualized diets are the most appropriate and thorough as they are adjusted to the characteristics and situation of each subject. A lot of information should be collected about the individual before starting to develop the diet to make it as thorough as possible. In order to achieve these objectives and to plan a diet, personal information should be obtained from the patient, such as age, sex, tastes and dietary restrictions, whether he or she has followed diets in the past and their objectives; the degree of health and the medical history should be taken into account, to only those foods that are appropriate for his or her state of health and to adjust the diet to improve or prevent disease; their physical activity, in order to know their habitual caloric expenditure to adjust the caloric intake and to provide suggestions to make it compatible with the diet; and finally, the data from a haematological and biochemical analysis, to know the state of the patient and to detect possible alterations that can be improved with the diet. An anthropometric study should also be carried out in order to evaluate the patient´s situation using parameters such as body mass index and to be able to follow the patient throughout the duration of the diet. All this information is taken as a starting point to be able to start planning the diet. This diet must be adjusted to the needs of the individual and prioritize the preservation or improvement of health and for this purpose it must provide all the necessary nutrients and in adequate quantities. It is also advisable to suggest the habituation to physical exercise and the proposal of other activities to increase the total physical activity in order to support the diet and healthy routines in the patient. Once the diet has been initiated by the subject, a follow up should be made of his/her evolution, with anthropometric parameters, and his/her opinion to try to evaluate if the diet is adapted to the patient, to improve it in the aspects that he/she considers worse or more difficult to follow and to make it as pleasant as possible to get the patient to follow it as faithfully as possible and to consider it as an opportunity to establish new habits that can be maintained in the long term. At the end of the period established for the diet or when the objectives are reached, an evaluation of the anthropometric parameters should be carried out again to check that the objectives have been reached in an appropriate way and a new haematological and biochemical analysis is recommended if his/her doctor considers it appropriate. If there is an opportunity and the patient so wishes, it is advisable to make a new evaluation some time after the completion of the diet to ensure that it does not return to the initial situation and, if so, to reconsider the diet, physical activity or the approach to changing habits.
In this project, three volunteers of different ages and sexes, with different starting points and objectives, have been chosen in order to elaborate an individualized diet for each one of a duration of four weeks. The previous study of each one of them was carried out and according to all the information gathered, four weekly diets were elaborated. At the end of each week, a follow-up was made taking into account the weight and opinion of each one in order to adapt the following weekly diet to the results and to the appreciations made by the volunteers. At the end of the diet, the whole process and the results were evaluated and a guide was proposed so that the patients could be autonomous and continue with the new habits d.