No description available.

Rationale: Published studies have shown that immigrants undergo dietary acculturation which may have positive or negative impact on their health. Therefore, a study was conducted to investigate this critical issue of dietary acculturation and any possible influence on the health status of newly arrived international students at Virginia Tech in Fall 2010. Design: In this study weight, fasting blood glucose and blood pressure of 35 international students (age 18-36 years) were determined at three time points, 5-6 weeks apart. Participants filled out a 20-item-questionnaire addressing alteration in the native and American dietary habits. Furthermore, 24 hrs dietary recalls and frequency of consuming the most popular food items in the US was assessed. Results: Total sample population (TSP) had a significant increase in average weight by 2.79 lbs from visit 1 (V1) to visit 3 (V3) (p=0.0082), Participants who gained weight (PGW; n=10) had an average increase by 9 lbs. Country wise, Chinese had a statistically significant average increase in their weights by 4.16 lbs (p=0.0077) whereas, Indians and Germans had an average increase by 2.36 lbs and 1.28 lbs respectively. Gender wise, the average increase in weight for females was 3.99 lbs (p=0.0015) while for males 1.52 lbs from V1 to V3. There were no significant differences in total caloric consumption from V1 to V3 for both groups of international students. There were no significant changes in the fasting blood glucose and systolic blood pressure from V1 to V3. There was an increase in frequency of consuming high calorie American food items in V3 when compared with V1. Frequency of burger consumption was highly increased in the TSP group while bagels were significantly increased in PGW group. There was an overall increasing trend towards American diet, cooking and eating habits. Finally, we conclude that the international students are gradually acculturating to the American diet and have impact on their weight which may potentially have a negative impact on their health status. Future studies and orientation program catered to the needs of adjusting to acculturation process of international students are recommended. / Master of Science

Background: Studies have consistently found a high prevalence of vitamin D deficiency in adolescents. Few validated dietary intake assessment tools for vitamin D exist for adolescents. Objective: The aim of this study was to determine if a short food frequency questionnaire (SFFQ) can be used to effectively assess vitamin D intake in adolescents compared to a previously validated long food frequency questionnaire (LFFQ). Participants/setting: 140 healthy 6-12 year old (male n=81) Caucasian and African American (n=94) children from Pittsburgh, Pennsylvania completed a SFFQ and LFFQ at two time points 6 months apart. Main outcome measures: Reliability and validity of a SFFQ by comparison with a previously validated LFFQ for children and adolescents. Statistical analysis: Reliability, validity, sensitivity, specificity, positive, and negative predictive values were assessed using Pearson correlation coefficients. Results: Mean vitamin D intake from the SFFQ (range, 434 to 485 IU) was higher than the LFFQ (range, 320 to 378 IU). Overall association between the SFFQ and the LFFQ for vitamin D intake was modest (r=0.36, P<0.001). When stratified by race, the overall degree of association was weak for African Americans (r=0.26, P=0.001) and moderate for Caucasians (r=0.57, P<0.001). Overall reliability testing results were modest and significant for the LFFQ (r=0.28, P=0.002) and SFFQ (r=0.33, P<0.001). Association between mean vitamin D intake from LFFQs and SFFQs was used to determine validity. The association for validity was found to be modest (r=0.51, P<0.001). Sensitivity, specificity, positive predictive value, and negative predictive value for the SFFQ were 90%, 64%, 0.78, and 0.58, respectively. Conclusion: The SFFQ was found to be modestly valid and reliable in an early adolescent population. Associations between African Americans were not as strong as Caucasians which may be due to errors in reporting dietary consumption related to higher body weight.

Protein is an important component of bone, but the role of dietary protein intake in osteoporosis remains controversial. The Utah picture-sort food frequency questionnaire was found to produce a useful estimation of usual dietary intake in the elderly. This method of dietary assessment was used in a population-based case-control study to examine the relationship between protein intake and risk of osteoporotic hip fracture in elderly Utah residents. Analyses of risk of hip fracture across increasing quartiles of protein intake were stratified by age-group. Higher protein intake was associated with a reduced risk of hip fracture in men and women aged 50-69 years but did not appear to increase or decrease risk of hip fracture in those aged 70-89 years. The relationship appeared to be modified by age. Modification of protein intake late in life may be a useful means to prevent hip fractures in the elderly.

No description available.

No description available.

Thesis (PhD)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: A comprehensive food frequency questionnaire (FFQ) was developed to assess the daily total flavonoid intake over the past fortnight within a 14-week intervention that consisted of four periods to determine the effect of rooibos consumption on oxidative stress in adults (n=40) at intermediate to high coronary heart disease (CHD) risk. Within the intervention the comprehensive FFQ validity (against six estimated dietary records and biomarkers), reproducibility (on administrations in the washout and control periods six weeks apart as these periods had similar flavonoid intake restrictions) and responsiveness (across the four intervention periods of changed dietary conditions) was evaluated. The baseline period dietary record and FFQ dietary sources found to contribute most to the participants’ daily total flavonoid intake, considering the percentage contribution, and the between-person variation in intake, considering the stepwise multiple regression analysis, formed the food list of the resultant abbreviated FFQ. The validity, reproducibility and responsiveness of the latter were also evaluated within the intervention and its validity (against dietary records) and reproducibility (on re-administration two weeks apart) in an additional group (n=90) being at low and intermediate CHD risk to evaluate its external strength. The validity and reproducibility evaluations of the comprehensive and abbreviated FFQs in the intervention and abbreviated FFQ within the additional group comprised paired difference tests (to establish the ability to estimate group intakes), correlation coefficients (to establish the ability to rank individual participants), category agreement and gross misclassification next to the weighted kappa statistic (to establish the ability to classify the participants into tertiles and quintiles of intake) and Bland-Altman plots (as representation of the limits of agreement between the two dietary assessment methods). Correlation coefficients were also used for biomarker validity evaluations in the baseline period. The repeated measures analysis of variance (ANOVA) (Bonferroni correction) was used for the responsiveness evaluations of the comprehensive and abbreviated FFQs across the intervention periods alongside that of the biomarkers as evidence for the changed dietary conditions. The study demonstrated that the comprehensive FFQ could be modified to a format with a brief food list as few items contributed appreciably to the total flavonoid intake and of which most also contributed to the between-person intake variability. The comprehensive and moreover the abbreviated FFQ in the validity evaluations provided sufficiently accurate daily total flavonoid intake estimates. They could determine the intake at group level in correspondence with that of the dietary records. The participant intakes could additionally be categorized and in particular ranked greatly alike to the dietary record intakes. The Bland-Altman plots revealed proportional bias regarding overestimation at the higher intake level. The reproducibility also appeared to be greatly satisfactory although seasonal fruit exclusions from the abbreviated FFQ food list may hamper its repeated administration. Both FFQs also confirmed the changed total flavonoid intakes across the intervention periods in relation to changes in the expected direction concerning the plasma total polyphenol, conjugated diene and thiobarbituric acid reactive substance concentrations. / AFRIKAANSE OPSOMMING: ‘n Omvattende voedsel frekwensie vraelys (VFV) is ontwikkel om die daaglikse totale flavonoïed inname oor twee agtereenvolgende weke te beraam te midde van ‘n 14-week intervensie. Die intervensie het uit vier periodes bestaan wat die effek van rooibosinname op oksidatiewe stres in volwassenes (n=40), met ‘n intermediêre tot hoë koronêre hartsiekte (KHS) risiko, bepaal het. Binne die intervensie is die geldigheid (teen ses geskatte dieetrekords en biochemiese merkers), herhaalbaarheid (op aanwending ses weke uitmekaar in die uitwas en kontrole intervensie periodes met dieselfde flavonoïed inname bepalings) en waarneembaarheid (oor vier intervensie periodes van veranderde dieet bepalings) van die omvattende VFV geëvalueer. Die dieetbronne in die basislyn periode dieetrekords en vraelyste wat die meeste tot die deelnemers se daaglikse totale flavonoïed inname (baseer op die persentasie bydrae) en die tussen-persoon variasie in inname (baseer op die stapsgewyse meervuldige regressie analise) bygedra het, het die voedsellys van die voortvloeiende verkorte VFV gevorm. Die geldigheid, herhaalbaarheid en waarneembaarheid van dié VFV is binne die intervensie geëvalueer en die geldigheid (teen dieetrekords) en herhaalbaarheid (heradministrasie twee weke later) daarvan in ‘n verdere groep (n=90) met lae en intermediêre KHS risiko as evaluasie van die eksterne vermoë van die VFV. Die geldigheid en herhaalbaarheid evaluasies van die omvattende en verkorte VFV in die intervensie en die verkorte VFV in die verdere groep het bestaan uit gepaarde verskil toetse (bepaling van die groepinname skattingsvermoë), korrelasie koëffisiënte (bepaling van individuele deelnemer rangorde skattingsvermoë), kategorie ooreenstemming en erge wanklassifikasie naas die aangepaste kappa statistiek (bepaling van die vermoë om die deelnemer innames in derdes en vyfdes te klassifiseer) en die Bland-Altman karterings (verteenwoordiging van ooreenstemmingslimiete tussen die twee dieetinname metodes). Korrelasie koëffisiënte is ook gebruik vir biochemiese merker geldigheid evaluasies in die basislyn periode. Die herhaalde metings analise van variansie (ANOVA) (Bonferroni regstelling) is gebruik om die waarneembaarheid evaluasies van die omvattende en verkorte VFV oor die intervensie periodes naas dit van die biochemiese merkers te evalueer as bewys van die veranderde dieet bepalings. Die studie het aangedui dat die omvattende VFV gewysig kon word tot ‘n formaat met ‘n verkorte voedsellys omdat slegs ‘n aantal items merkbaar tot die totale flavonoïed inname bygedra het en die meeste hiervan ook tot die tussen-persoon variasie in inname. Die omvattende en die verkorte VFV het in die geldigheid evaluasies daarvan voldoende akkurate daaglikse totale flavonoïed inname skattings opgelewer omdat groep innames bepaal kon word in ooreenstemming met dit verkry van die dieetrekords en die deelnemer innames bykomend kategoriseer en in besonder grootliks eenders rangeer kon word as met hul dieetrekord innames. ‘n Proporsionele oorskatting by die hoër inname vlakke is wel vir al twee getoon in die Bland-Altman karterings. Die herhaalbaarheid was ook grootliks aanvaarbaar, alhoewel seisoenale vrugte uitsluitings in die verkorte VFV voedsellys die heruitvoering kan bemoeilik. Al twee vraelyste kon ook die veranderinge in die daaglikse totale flavonoïed inname oor die intervensie periodes bevestig in ooreenstemming met veranderinge in die verwagte rigting van die plasma totale polifenool, konjugaat diëne en tiobarbituursuur reaktiewe stof konsentrasies.

Introdução: A avaliação da dieta habitual do adolescente é complexa devido às variações intra e interindividuais. Os estudos de validação e reprodutibilidade de questionários de freqüência alimentar são necessários para garantir a utilização de instrumentos capazes de mensurar a dieta habitual real. Objetivo: Desenvolver, verificar a validade e reprodutibilidade de um questionário de freqüência alimentar baseado nos grupos alimentares da pirâmide alimentar para adolescentes (QFA-PA). Materiais e métodos: Após a identificação dos alimentos a serem incluídos no QFA-PA, o método foi testado em estudo piloto. A versão final consistiu em 50 itens alimentares. O estudo foi realizado com 109 adolescentes de ambos os gêneros durante um período de quatro meses. Para verificar a validade e reprodutibilidade do QFA-PA foram aplicados quatro Recordatórios de 24h (Rec24h) e dois QFA-PA. A validade foi obtida pela comparação entre o segundo QFA-PA e à média dos Rec24h. A reprodutibilidade foi mensurada por meio da comparação dos dois QFA-PA. Resultados: O questionário desenvolvido representou 97,7% das calorias consumidas e pelo menos 90% da ingestão dos nutrientes selecionados. Foram incluídos os alimentos freqüentemente relatados ausentes no QFA e freqüentemente relatados sem maior contribuição energética. As variáveis melhor avaliadas foram os grupos do arroz, pão, massa, batata e mandioca; das carnes e de açúcares e doces. Os piores resultados foram observados para a vitamina C. Cabe ressaltar que este é o primeiro QFA desenvolvido, validado e acurado no Brasil para adolescentes que avalia o consumo alimentar baseado na pirâmide dos alimentos dos adolescentes. Conclusão: Considerando-se as análises realizadas, o QFA-PA apresentou validade satisfatória e reprodutibilidade aceitável para a maioria das variáveis. / Introduction: The assessment of habitual diet of adolescent is complex due to within and between-person variations. The studies of validity and reproducibility of food frequency questionnaire (FFQ) are needed to ensure the use of reliable and accurate instruments capable of measure usual diet. Objective: To develop, verify the validity and reproducibility of a food frequency questionnaire based on the food groups of food pyramid for adolescents (FFQ-PA). Methods: After identify the items to be included in the FFQ-PA, the method was tested in a pilot study. The final version consisted of 50 food items. The study was conducted with 109 adolescents of both genders over a period of four months. To check the validity and reproducibility of the FFQ-PA were applied four 24-hour records (Rec24h) and two FFQ-PA. The validity was obtained by comparing the second FFQ-PA and average Rec24h. The reproducibility was measured by comparing the two FFQ-PA. Results: The questionnaire represented 97,7% of the calories consumed by the population and at least 90% of the intake of selected nutrients. We included food often reported missing in the FFQ and the frequently reported without further energy contribuition. In the study of validity and reproducibility, the variables were evaluated further groups of rice, bread, pasta, potatoes and cassava, meat and sugar and sweets. The worst results were observed for vitamin C. It is noteworthy that this is the first FFQ developed, validated and accurate in Brazil for adolescents that assesses food consumption based on the adolescent food pyramid. Conclusion: Considering the analysis, the FFQ-PA showed satisfactory validity and reproducibility acceptable for most variables.

Objetivos: Desenvolver um questionário quantitativo de freqüência alimentar para gestantes adultas usuárias do Sistema Único de Saúde de Ribeirão Preto, SP. Metodologia: A coleta de dados foi realizada de junho a outubro de 2008. Um inquérito recordatório de 24 horas (IR24h) foi obtido de 150 gestantes, 50 em cada trimestre gestacional, com idade entre 18 e 35 anos. Um segundo IR24hs foi obtido de uma subamostra com 90 gestantes, 30 em cada trimestre gestacional, entre 7 e 15 dias após o primeiro inquérito. A elaboração da lista de alimentos foi feita a partir da contribuição percentual de cada alimento para a estimativa total de energia e nutrientes de interesse. As porções alimentares foram determinadas de acordo com a distribuição percentual dos pesos relatados e descritas em percentis, sendo o P50 correspondente à porção de referencia (média), e as porções pequena, grande e extra grande, aos percentis 25, 75 e 100, respectivamente. Os dados de estimativa dos nutrientes foram ajustados pela energia e variância. Os testes de X², ANOVA, Tuckey e Kruskal-Wallis foram empregados para investigar diferenças segundo trimestre gestacional. Os softwares Nutwin e SPSS foram usados para a análise dos inquéritos recordatórios e análise estatística, respectivamente. P<0,05 foi estipulado como significante. Resultados: No total, 305 alimentos e preparações foram relatados nos IR24h e agrupados em 112 itens segundo similaridade do valor nutricional por porção alimentar. Diferentes itens alimentares foram relatados nos inquéritos recordatórios segundo período gestacional, tendo sido encontradas diferenças quanto às estimativas de ingestão dos nutrientes. O tamanho das porções alimentares foi diferente para tomate e doces à base de leite. O questionário com 85 itens alimentares representou 96% dos macronutrientes e 74,2 a 98,8% dos nutrientes de interesse selecionados. Conclusão: O questionário desenvolvido possui um número razoável de itens, que contempla as principais fontes alimentares dos nutrientes de interesse na gestação. Este é o primeiro questionário quantitativo de freqüência alimentar desenvolvido para gestantes brasileiras. As analises quanto à acurácia e precisão do questionário estão em andamento. / Objective: To design a quantitative food frequency questionnaire for pregnant women attended by the Brazilian National Health Service in Ribeirão Preto, SP. Methods: Data were obtained from June to October of 2008. A 24-hour food recall was obtained from 150 women, 50 in each trimester of pregnancy, aged 18-35 years. A second food recall was obtained from 90 women, 30 in each trimester of pregnancy, from 7 to 15 days after the first dietary assessment. The development of the food list was based on the contribution to the total population intake of relevant nutrients by each food item. The portion sizes were determined according to percentiles of intake of each food item, and P50 corresponded to the reference portion (medium), and small, large and extra-large to P25, P75 and P100, respectively. Data were adjusted for energy intake and within-subject variance. Chi-square, ANOVA, Tuckey and Kruskal-Wallis were used to investigate differences according to gestational age. Nutwin and SPSS software were used for the analysis of dietary intake and statistics, respectively. P < 0.05 was taking as significant. Results: Totally, 305 foods and preparations were reported on the food recalls, and grouped into 112 items according to similarity in nutrient content per usual serving size. Distinct food items were reported on food recalls according to gestational age, and differences for the estimative of nutrient intakes were found. For portion sizes, differences were found for tomato and candies made with milk and sugar. The food frequency questionnaire was designed with 85 items, which represented 96% of the macronutrient intake and from 74,2 to 98,8% of other nutrients of interest. Conclusions: The food frequency questionnaire has a reasonable number of food items, which represented the mainly sources of nutrients of interest for pregnancy. This is the first food frequency questionnaire designed for Brazilian pregnant women. Investigations of the accuracy and precision of the questionnaire are being carried out.

Objetivos: Desenvolver um questionário quantitativo de freqüência alimentar para gestantes adultas usuárias do Sistema Único de Saúde de Ribeirão Preto, SP. Metodologia: A coleta de dados foi realizada de junho a outubro de 2008. Um inquérito recordatório de 24 horas (IR24h) foi obtido de 150 gestantes, 50 em cada trimestre gestacional, com idade entre 18 e 35 anos. Um segundo IR24hs foi obtido de uma subamostra com 90 gestantes, 30 em cada trimestre gestacional, entre 7 e 15 dias após o primeiro inquérito. A elaboração da lista de alimentos foi feita a partir da contribuição percentual de cada alimento para a estimativa total de energia e nutrientes de interesse. As porções alimentares foram determinadas de acordo com a distribuição percentual dos pesos relatados e descritas em percentis, sendo o P50 correspondente à porção de referencia (média), e as porções pequena, grande e extra grande, aos percentis 25, 75 e 100, respectivamente. Os dados de estimativa dos nutrientes foram ajustados pela energia e variância. Os testes de X², ANOVA, Tuckey e Kruskal-Wallis foram empregados para investigar diferenças segundo trimestre gestacional. Os softwares Nutwin e SPSS foram usados para a análise dos inquéritos recordatórios e análise estatística, respectivamente. P<0,05 foi estipulado como significante. Resultados: No total, 305 alimentos e preparações foram relatados nos IR24h e agrupados em 112 itens segundo similaridade do valor nutricional por porção alimentar. Diferentes itens alimentares foram relatados nos inquéritos recordatórios segundo período gestacional, tendo sido encontradas diferenças quanto às estimativas de ingestão dos nutrientes. O tamanho das porções alimentares foi diferente para tomate e doces à base de leite. O questionário com 85 itens alimentares representou 96% dos macronutrientes e 74,2 a 98,8% dos nutrientes de interesse selecionados. Conclusão: O questionário desenvolvido possui um número razoável de itens, que contempla as principais fontes alimentares dos nutrientes de interesse na gestação. Este é o primeiro questionário quantitativo de freqüência alimentar desenvolvido para gestantes brasileiras. As analises quanto à acurácia e precisão do questionário estão em andamento. / Objective: To design a quantitative food frequency questionnaire for pregnant women attended by the Brazilian National Health Service in Ribeirão Preto, SP. Methods: Data were obtained from June to October of 2008. A 24-hour food recall was obtained from 150 women, 50 in each trimester of pregnancy, aged 18-35 years. A second food recall was obtained from 90 women, 30 in each trimester of pregnancy, from 7 to 15 days after the first dietary assessment. The development of the food list was based on the contribution to the total population intake of relevant nutrients by each food item. The portion sizes were determined according to percentiles of intake of each food item, and P50 corresponded to the reference portion (medium), and small, large and extra-large to P25, P75 and P100, respectively. Data were adjusted for energy intake and within-subject variance. Chi-square, ANOVA, Tuckey and Kruskal-Wallis were used to investigate differences according to gestational age. Nutwin and SPSS software were used for the analysis of dietary intake and statistics, respectively. P < 0.05 was taking as significant. Results: Totally, 305 foods and preparations were reported on the food recalls, and grouped into 112 items according to similarity in nutrient content per usual serving size. Distinct food items were reported on food recalls according to gestational age, and differences for the estimative of nutrient intakes were found. For portion sizes, differences were found for tomato and candies made with milk and sugar. The food frequency questionnaire was designed with 85 items, which represented 96% of the macronutrient intake and from 74,2 to 98,8% of other nutrients of interest. Conclusions: The food frequency questionnaire has a reasonable number of food items, which represented the mainly sources of nutrients of interest for pregnancy. This is the first food frequency questionnaire designed for Brazilian pregnant women. Investigations of the accuracy and precision of the questionnaire are being carried out.