RESUMEN
BACKGROUND: It is of great value to develop valid instruments to estimate food consumption; for this purpose, the triads method has been applied in validation studies of dietary intake to evaluate the correlation between three measurements [food frequency questionnaire (FFQ), reference method and biomarker]. The main aim of the present study was to validate a FFQ for Brazilian adults by means of the method of triads by estimating the ingestion of total fatty acids based on the level of saturation. METHODS: The present study enrolled 152 Brazilian adults of both sexes, who were residents in the city of Viçosa, Brazil. The ingestion of total saturated, monounsaturated, polyunsaturated, trans, linoleic and linolenic fatty acids was assessed by means of a FFQ, two food records, and biomarkers, which were detected by gas chromatography. The validation coefficients were calculated using the method of triads and concordance was determined by Kappa statistics. RESULTS: The FFQ was considered an adequate dietary method, because, based on the validation coefficients, it estimates the intake of total fat (0.84), as well as linolenic (0.90) and linoleic acids (0.31). A high concordance rate was confirmed for all nutrients assessed by the FFQ and food records. Regarding the biomarkers, linolenic acid and linoleic acid presented greater concordance. CONCLUSIONS: According to the validation coefficients, the FFQ precisely estimated total fat, linolenic acid and linoleic acid contents.
Asunto(s)
Encuestas sobre Dietas/normas , Dieta , Grasas de la Dieta/administración & dosificación , Ácidos Grasos/administración & dosificación , Conducta Alimentaria , Adulto , Brasil , Registros de Dieta , Ingestión de Alimentos , Femenino , Humanos , Ácido Linoleico/administración & dosificación , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Encuestas y Cuestionarios , Adulto Joven , Ácido alfa-Linolénico/administración & dosificaciónRESUMEN
BACKGROUND/OBJECTIVES: Food fortification is an important strategy in public health policy for controlling micronutrient malnutrition and a major contributing factor in the eradication of micronutrients' deficiencies. Approximately 50 countries worldwide have adopted food fortification with folic acid (FA). FA fortification of wheat and maize flours has been mandatory in Brazil since 2004. To assess the effect of 10 years of FA food fortification policy on folate status of residents of São Palo, Brazil using a population-based survey. SUBJECTS/METHODS: Data were from 750 individuals aged ⩾12 years who participated in a cross-sectional population-based survey in São Paulo city, Brazil. Fasting blood samples were collected, and folate was assayed by affinity-high performance liquid chromatografy method with electrochemical detection. The participants provided information about food intake based on two 24 h dietary recall. RESULTS: Only 1.76% of population had folate deficiency (<6.8 nmol/l). The mean folate concentration was 29.5 (95% confidence interval: 27.3-31.7) nmol/l for all sex-age groups. The mean folate intake for the population was 375.8 (s.e.m.=6.4) µg/day of dietary folate equivalents (DFEs). When comparing folate intake in DFE from food folate and FA from fortified foods, FA contributed 50% or more of the DFE in almost all sex-age groups. The major contributors of folate intake are processed foods made from wheat flour fortified with FA, especially among subjects younger than 20 years old. CONCLUSIONS: The deficiency of folate is very low, and food fortification contributed to folate intake and had a notable influence on rankings of food contributors of folate.
Asunto(s)
Deficiencia de Ácido Fólico/prevención & control , Ácido Fólico/administración & dosificación , Alimentos Fortificados , Política de Salud , Evaluación de Resultado en la Atención de Salud , Adolescente , Adulto , Anciano , Brasil/epidemiología , Niño , Preescolar , Estudios Transversales , Femenino , Ácido Fólico/sangre , Deficiencia de Ácido Fólico/sangre , Deficiencia de Ácido Fólico/epidemiología , Humanos , Lactante , Masculino , Persona de Mediana Edad , Encuestas Nutricionales , Estado Nutricional , Adulto JovenRESUMEN
UNLABELLED: BACKGROUNDS/OBJECTIVES: The aim of this paper is to verify the performance of the frequency of consumption as variable for prediction of the usual intakes of foods. SUBJECTS/METHODS: In total, 725 individuals who answered two nonconsecutive 24-h recall and one food frequency questionnaire (FFQ) in the 'Healthy Survey-Sao Paulo-Brazil'. An additional indicator variable indicating if one is usual consumer was created before analyzing. The Multiple Source Method and National Cancer Institute method were used to estimate usual intake of selected food considering different models of prediction: with no covariates; with FFQ; with FFQ plus indicator variable; and with only indicator variable. RESULTS: For foods that are consumed every day or almost every day, the inclusion of the FFQ and/or the indicator variable as covariates resulted in similar percentiles of consumption when compared with the model with no covariates. For episodically consumed foods, the models with FFQ plus indicator variable and with only indicator variable estimated similar percentiles of intake. CONCLUSIONS: The use of the indicator variable instead the FFQ appears as a good alternative to estimate usual intake of episodically consumed foods.
Asunto(s)
Encuestas sobre Dietas/normas , Dieta , Ingestión de Energía , Conducta Alimentaria , Encuestas y Cuestionarios/normas , Brasil , Humanos , Modelos Biológicos , Reproducibilidad de los ResultadosRESUMEN
BACKGROUND: Given the importance of both calcium and vitamin D for bone health and the high prevalence of vitamin D from around the world, the present study aimed to evaluate calcium and vitamin D intake in a group of healthy Brazilian adolescents and young adults and to examine the influence of breakfast and dairy products in the total intake of these nutrients. METHODS: One hundred and sixty adolescents and young adults, aged 16-20 years old, from a public school, participated in the present study. Three-day dietary records were used to assess calcium and vitamin D intakes. Serum 25(OH)D levels were measured using a radioimmunoassay kit. The results were expressed as the mean (SD). RESULTS: Only 3.8% of the subjects met the daily adequate intake recommendation for calcium, and none for vitamin D [682.2 (132.2)mg day(-1) and 124.0 (28.0)IU day(-1) , respectively]. 25(OH)D serum levels were insufficient in 51.5% and deficient in 9.7% of the individuals [72.5 (22.3) nmol L(-1) ]. There was a significant positive correlation between dairy product intake with both calcium and vitamin D (r=0.597 and r =0.561, respectively; P=0.000). Adolescents who ate breakfast had a significant higher mean calcium, vitamin D and dairy product intake than adolescents who did not report this meal. CONCLUSIONS: The majority of adolescents and young adults did not consume recommended intakes of calcium and vitamin D and also presented 25(OH)D insufficiency. The results indicate that a regular breakfast and the consumption of dairy products represent important strategies in improving calcium and vitamin D intake in the diet.