Identificador: TDX:500
Autors: Capdevila Muñoz, Francesca
Resum:
OF THE THESIS ENTITLED: DYNAMICS OF THE COMPONENTS OF THE ENERGY INTAKE ALONG THE DIFFERENT STAGES OF LIFE. Francesca Capdevila Muñoz Objectives: To describe which are the changes in energy intake, energy density and food volume that take place in a healthy population, according to age and sex, and to determine the relative role of energy density and food volume in the achievement of the energy intake which is necessary in each stage of life. We also try to see whether the dynamics established between these two factors is comparable between two populations of different genetic, social and cultural characteristics, like the children from Reus (Spain) and the ones from Guadalajara (Mexico).Material and methods: Project that consists of three observational, cross-sectional and prospective studies. A) Study of the food and nutritional intake in a group of 120 children during the dietary diversification age (4 to 12 months old). B) Study of the food and nutritional intake in a sample of the Reus population, aged from 1 to 98 years old. C) Comparison of the food and nutritional intake of a sample of 1 to 4 year-old Mexican children with a sample of the Reus population of the same ages. In the three studies, from the data obtained by means of 24-hour recalls, the mean intakes of the different food groups were calculated and the values of daily energy intake (kcal/day) and macronutrients (g/day of proteins, lipids and carbohydrates) were quantified.We also calculated the food volume, the dietary energy density, the percentage of total energy provided by each macronutrient, the energy intake per kg of body weight and the food volume per kg of body weight. Results and conclusions: From infancy to the end of puberty there is a progressive increase of the energy intake, the food volume and the energy density of the diet. At the pubertal age significant differences between sexes are established in the variables analysed. During adulthood there is a significant tendency (p<0.001 in both sexes) towards a decrease in the energy intake and in the energy density of the diet. The food volume shows a progressive increase from the second year of life onwards; however, in adulthood this variable does not show a significant tendency towards a decrease in women and, in men, the descent of the food volume begins from the age of 45 and it is much less pronounced than that observed in the energy density.When we compare the children from Reus with the sample of Mexican children, we observe that the existing differences between the diets of both countries determine a different energy density, so the Mexican children eat a greater food volume in order to obtain the necessary energy intake from a less dense diet.The percentage of total energy intake that is provided by proteins and lipids exceeds the recommendations in nearly all the age groups, whereas the percentage provided by carbohydrates rarely achieves a 50%.From the analysis of these three studies we can see that, along the different life stages, the variation in the energy intake ─due to physiological changes in the energy requirements─ is achieved basically by means of variations in the energy density of the diet, although in certain moments, when the energy requirements increase momentarily or the diet has a low energy density, we also observe an increase in the volume of foods consumed. Whereas, with age, as the requirements tend to decrease, we don't find a decrease of the food volume parallel to the one observed both in the energy intake and in the energy density.
Repositori URV