Seasonal variation of food intake of adults from Niterói, Rio de Janeiro, Brazil.

The measurement of usual food intake (FI) is necessary to accurately establish the relationship between diet and disease. In most studies data are collected at one particular time of the year, which may influence the interpretation of the results. The purpose of this study was to investigate the effect of seasonality on FI in a sample of adults from Niterói, RJ, Brazil. A total of 102 healthy subjects (69 women) aged between 20 and 69 years were interviewed to obtain six 24-hour dietary recalls, three in summer and three in winter. In both seasons, the intake of energy (EI) and 23 nutrients was determined and the percent of subjects who met the recommendations for the nutrients were computed. The data of FI were deattenuated considering the within-person variability and adjusted for energy. The intake of energy and some nutrients were significantly different between men and women. EI did not differ between seasons, for both sexes, but the intake of macro and micronutrients was different. The results of this study suggest that the seasonality in the measurement of FI should be considered in order to improve the methods and instruments used in population dietary surveys.