Development of a quantitative food frequency questionnaire for adults on the Northeast of Brazil.
Food frequency questionnaire; Food consumption; Questionnaire survey; Ultra processed foods.
Among the various methods of dietary surveys there is the Food Frequency Questionnaire (FFQ), an instrument generally used in epidemiological studies in order to evaluate the binomial, diet versus disease. Given the importance to evaluate the food consumption of the populations for the understanding of the relationship between health and diet, this paper proposes to develop a quantitative food frequency questionnaire for the adult population in northeast of Brazil based in a national survey, and considering the level of food processing for the food items. The development of the FFQ was performed using data from a cross-sectional study of national scope. For the development were used the Micro-data of the individual food consumption module and also the data from the residents of the 2008-2009 Family Budgets Survey, on a sample (n = 7,516) of the Brazilian northeast population between 20 and 59 years. After the adjustments were made, the food consumption data stayed with 404 food items. Those were used for the construction of the food lists, the first step to develop the FFQ. To the construct we opted for the methodology of relative contribution of the item, in which were identified the food items with the highest relative contribution for the energy and the nutrients of interest- macronutrients, saturated fat, vitamin A, vitamin C, vitamin D, vitamin E, iron, sodium, calcium, selenium, magnesium, copper and zinc. To compose the food lists, those responsible for up to 90% of the nutrient contribution were considered, or even those that are considered sources of a nutrient of interest. The lists pointed a consumption of traditional foods and minimally processed foods, more consumed in the list of calories, like rice (11.41%) and beans (8.44%). As a downside, the nutrient’s lists, such as trans-fat and sodium, have had their majority contribution in ultra-processed foods. For the development of FFQ, the final list included 97 foods that have been grouped according to their level of food processing, using to the NOVA classification system of food, on unprocessed or minimally processed foods, processed culinary ingredients and processed foods, and ultra-processed food and drink products. To determine the portion of food to compose the FFQ, the quartiles of weights were calculated from the selected foods, in which P50 was the middle portion, P25, the small one, P75, the large and P95, the extra-large portion. The time considered was the previous year. The development of the FFQ represents a breakthrough in nutritional epidemiology regional area since the development of this type of instrument in this region of Brazil is new, and taking into account the new panorama of debates on food and nutrition, the instrument innovates with the classification of foods according to the extent and purpose of food processing.