Validation of a food-frequency questionnaire for the assessment of calcium intake in schoolchildren aged 9-10 years

Iodine-specific food frequency questionnaire can evaluate iodine intakes of Chinese pregnant women

Iodine is an essential trace element for the synthesis of thyroid hormones, which play an important role in growth and development, metabolism, and body organ function. There is no iodine-specific food frequency questionnaire (I-FFQ) for pregnant women in China. This study aimed to validate and optimize an I-FFQ. A total of 1802 pregnant women were included in this study. The iodine nutrition survey was performed using I-FFQ and 3-day estimated food diary (3DEFD). Seventy-one women of reproductive age repeated the I-FFQ twice to assess for FFQ reproducibility. Further optimization of the I-FFQ was accomplished by integrating iodine contributions to simplified questionnaire items. Correlation and Bland-Altman analyses were used to verify the consistency of I-FFQ with 3DEFD, as well as the stability and feasibility of I-FFQ optimization. The I-FFQ and 3DEFD had a strong correlation (R = 0.76, P < .001) and agreement (Kappa = 0.731, P < .001). A Bland-Altman plot showed that 5.1% of participants exceeded the limit of agreement. Nonpregnant women of reproductive age completed the I-FFQ twice, and the results had a strong correlation (R = 0.72, P < .001). A Bland-Altman analysis showed that 5.6% of individuals were located outside the limit of agreement. The consistency of I-FFQ before and after optimization was good (Kappa = 0.982, P < .001). Therefore, I-FFQ could be used as a valid tool to estimate iodine intake among Chinese pregnant women. The optimized I-FFQ could shorten survey time without affecting its accuracy.

Relative validity of FFQ to assess food items, energy, macronutrient and micronutrient intake in children and adolescents: a systematic review with meta-analysis

FFQ are one of the most widely used tools of research into nutritional epidemiology, and many studies have been conducted in several countries using this dietary assessment method. The present study aimed to evaluate the relative validity of FFQ, in comparison with other methods, in assessing dietary intake of children and adolescents, through a systematic review. Four electronic databases (Embase, PubMed, Scopus and Web of Science) found sixty-seven articles, which met the inclusion criteria (healthy children and adolescents from 3 to 18 years of age; journal articles written in English, Spanish and Portuguese between 1988 and March 2019; results showing the comparison between the FFQ with other methods of assessment of dietary intake). The articles were analysed by two independent reviewers. A meta-analysis was conducted using correlation coefficients as estimate effects between the FFQ and the reference standard method. Subgroup analysis and meta-regression were performed to identify the probable source of heterogeneity. In fifty-five of the sixty-seven studies, a single dietary assessment method was used to evaluate the FFQ; nine combined the two methods and three used three reference methods. The most widely used reference method was the 24-h recall, followed by the food record. The overall relative validity of the FFQ to estimate energy, macronutrient, certain micronutrient and certain food item intakes in children and adolescents may be considered weak. The study protocol was registered in PROSPERO under number CRD42016038706.

The dietary management of calcium and phosphate in children with CKD stages 2-5 and on dialysis-clinical practice recommendation from the Pediatric Renal Nutrition Taskforce

In children with chronic kidney disease (CKD), optimal control of bone and mineral homeostasis is essential, not only for the prevention of debilitating skeletal complications and achieving adequate growth but also for preventing vascular calcification and cardiovascular disease. Complications of mineral bone disease (MBD) are common and contribute to the high morbidity and mortality seen in children with CKD. Although several studies describe the prevalence of abnormal calcium, phosphate, parathyroid hormone, and vitamin D levels as well as associated clinical and radiological complications and their medical management, little is known about the dietary requirements and management of calcium (Ca) and phosphate (P) in children with CKD. The Pediatric Renal Nutrition Taskforce (PRNT) is an international team of pediatric renal dietitians and pediatric nephrologists, who develop clinical practice recommendations (CPRs) for the nutritional management of various aspects of renal disease management in children. We present CPRs for the dietary intake of Ca and P in children with CKD stages 2-5 and on dialysis (CKD2-5D), describing the common Ca- and P-containing foods, the assessment of dietary Ca and P intake, requirements for Ca and P in healthy children and necessary modifications for children with CKD2-5D, and dietary management of hypo- and hypercalcemia and hyperphosphatemia. The statements have been graded, and statements with a low grade or those that are opinion-based must be carefully considered and adapted to individual patient needs based on the clinical judgment of the treating physician and dietitian. These CPRs will be regularly audited and updated by the PRNT.

Validation of a Food Frequency Questionnaire to Assess Intake of n-3 Polyunsaturated Fatty Acids in Switzerland

Population-based data suggest that high intake of omega-3 (n-3) polyunsaturated fatty acids (PUFA) may be beneficial in a variety of health conditions. It is likely that mainly those patients with preexisting n-3 deficiency are those that benefit most from n-3 fatty acid supplementation. Therefore, for targeted interventions, a fast and reliable screening tool for n-3 PUFA intake is necessary. Thus, the aim of this project was to adapt and validate a food frequency questionnaire (FFQ) for n-3 PUFA intake in Switzerland while using as references the following: (1) 7-day food records (FR), and (2) n-3 fatty acid composition of red blood cells (RBC). We recruited 46 healthy adults for the first part of the study and 152 for the second. We used the dietary software EBISpro for the analysis of n-3 PUFA intake. RBC fatty acid composition was determined by gas chromatography mass spectrometry (GC-MS). Using correlation analysis, we found a moderate significant association between FFQ and FR for α-linolenic acid (ALA), eicosapentanoic acid (EPA), docosahexanoic acid (DHA), and total n-3 fatty acids (all r between 0.523 and 0.586, all p < 0.001). Bland Altman analysis further showed good agreement between the two methods and no proportional bias. Correlations between FFQ and RBC fatty acid composition were also moderate for EPA and DHA (r = 0.430 and r = 0.605, p < 0.001), but weaker for ALA and total n-3 (r = 0.314 and r = 0.211, p < 0.01). The efficacy of the FFQ to classify individuals into the same or adjacent quartile of RBC PUFA content ranged between 70% and 87% for the different fatty acids. In conclusion, we showed that the Swiss n-3 PUFA FFQ is a valid tool to assess dietary n-3 PUFA intake, especially DHA and EPA, to determine population groups at risk for low intake.

Reproducible and reliable general semiquantitative food frequency questionnaire for evaluating iodine intake in Chinese children

Iodine deficiency is a global issue that is correlated with a variety of diseases and can affect individuals of all ages. We hypothesized that a general, semiquantitative food frequency questionnaire (FFQ) could be a valuable tool to evaluate iodine intake in children. Study participants comprised 687 healthy children between the ages of 7 and 13 years. The FFQ was developed to assess habitual iodine intake over a 6-month period (FFQ1). A 3-day estimated food diary (3DEFD) and the habitual daily iodine intake, calculated from 2-repeated 24-hour urine iodine excretion, tested the intermethod relative validity of the FFQ. There were 92 children who also repeated the FFQ (FFQ2) 3 weeks later to assess for FFQ reproducibility. Iodine intake estimated by FFQ1 + water was significantly higher than that indicated by the 3DEFD + water (204 μg/d vs 156 μg/d, P < .001), whereas there were no differences between habitual daily iodine intake and FFQ1 + water (185 μg/d vs 204 μg/d, P = .223). The interclass correlation coefficients of iodine intake estimated by the FFQ1 and FFQ2 were 0.72 (P < .001). The FFQ1 + water was moderately correlated with the 3DEFD + water (Spearman correlation coefficient = 0.57, P < .001) as well as habitual daily iodine intake (SCC = 0.34, P < .001). The subjects classified into the same or adjacent quartiles ranged from 32% to 93%. The κ value α was 0.46 for FFQ1 and FFQ2 (P < .001) 0.27 for FFQ1 + water and 3DEFD + water (P < .001), and 0.09 for FFQ1 + water and habitual daily iodine intake (P < .001). The results showed this FFQ is a reliable and reproducible tool in evaluating iodine intake in Chinese children.

Development of a Food Frequency Questionnaire for Assessing Dietary Intake in Children and Adolescents in South America

OBJECTIVE

This study aimed to describe the development of a food frequency questionnaire (FFQ) to assess dietary intake in South American children and adolescents.

METHODS

A total of 345 children (aged 3-10 years) and 357 adolescents (aged 11-17 years) were included for analysis. The FFQ was designed to be self-administered and to assess dietary intake over the past 3 months. It was developed in Spanish and translated into Portuguese. Multiple approaches were considered to compile the food list, and 11 food groups were included. A food photo booklet was produced as supporting material.

RESULTS

The FFQ items maintained a common core list among centers (47 items) and country-specific foods. The FFQ for Buenos Aires and Lima had a total of 63 items; there were 55 items for the FFQ in Medelin, 60 items for Montevideo, 58 items for Santiago, 67 items for Sao Paulo, and 68 items for Teresina. Alcohol was also incorporated in the adolescents' FFQ.

CONCLUSIONS

We developed a semiquantitative, culturally adapted FFQ to assess dietary intake in children and adolescents in South America. It has an optimal size allowing its completion in a high proportion of the population; therefore, it can be used in epidemiological studies with South American children and adolescents.

Rapid assessment of dietary calcium intake

A five-food item food frequency questionnaire (FFQ) and a 3-day food diary (3DFD) were used to estimate daily dietary calcium (Ca) intake in 32 patients aged 1-17 years. Median and IQR of Ca intake from 3DFD was 840 mg and 438 mg while from FFQ it was 700 mg and 987 mg, respectively. The non-parametrical Bland-Altman limits of agreement plot between two methods showed that most of the values fell between the limits of agreement at +794 mg and -388 mg. The FFQ had a specificity of 93% in identifying children who consumed inadequate amount of dietary Ca and a sensitivity of 78% in identifying children whose dietary Ca intake exceeded UK's Reference Nutrient Intake. Thus the FFQ allows rapid estimation of children with low daily dietary Ca intake in the clinic setting; however it does not replace 3DFD.

Reproducibility and Relative Validity of a Short Food Frequency Questionnaire in 9-10 Year-Old Children

The aim of this study was to assess the reproducibility and validity of a non-quantitative 28-item food frequency questionnaire (FFQ). Children aged 9-10 years (n = 50) from three schools in Dunedin, New Zealand, completed the FFQ twice and a four-day estimated food diary (4DEFD) over a two-week period. Intraclass correlation coefficients (ICC) and Spearman's correlation coefficients (SCC) were used to determine reproducibility and validity of the FFQ, respectively. Weekly intakes were estimated for each food item and aggregated into 23 food items/groups. More than half of the food items/groups (52.2%) had an ICC ≥0.5. The median SCC between FFQ administrations was 0.66 (ranging from 0.40 for processed meat to 0.82 for sweets and non-dairy drinks). Cross-classification analysis between the first FFQ and 4DEFD for ranking participants into thirds showed that breakfast cereals had the highest agreement (54.0%) and pasta the lowest (34.0%). In validity analyses, 70% of food items/groups had a SCC ≥0.3. Results indicate that the FFQ is a useful tool for ranking children according to food items/groups intake. The low respondent burden and relative simplicity of the FFQ makes it suitable for use in large cohort studies of 9-10 year-old children in New Zealand.

Growing Strong and Healthy with Mister Bone: An Educational Program to Have Strong Bones Later in Life

Optimal peak bone mass and bone health later in life are favored by a sufficient calcium intake in infancy, childhood and adolescence. The purpose of this study was to test a new educational program created to monitor and to improve calcium and vitamin D intake in children. Nutritional habits in children were evaluated through a food frequency questionnaire (FFQ) to assess the intake of calcium, vitamin D, dairy products, and total caloric energy at baseline and after seven months of exposure to a unique educational program applied between November 2013 and May 2014 in 176 schoolchildren (48% male, 52% female) attending the fourth and fifth grades of two selected primary schools in Florence, Italy. A significant increase of calcium (from 870 ± 190 to 1100 ± 200 mg/day, p < 0.05), and vitamin D (from 3.6 ± 1.53 to 4.1 ± 2 µg/day) intake in children was documented after the educational program. The amount of specific foods important for bone health consumed, such as milk and vegetables, increased significantly, both in male and female children (p < 0.05). The proposed educational program appears to be effective in modifying calcium intake in children, with a significant increase in the consumption of dairy products and vegetables, but without a significant change in the total caloric intake.

Application and interpretation of multiple statistical tests to evaluate validity of dietary intake assessment methods

BACKGROUND

Several statistical tests are currently applied to evaluate validity of dietary intake assessment methods. However, they provide information on different facets of validity. There is also no consensus on types and combinations of tests that should be applied to reflect acceptable validity for intakes. We aimed to 1) conduct a review to identify the tests and interpretation criteria used where dietary assessment methods was validated against a reference method and 2) illustrate the value of and challenges that arise in interpretation of outcomes of multiple statistical tests in assessment of validity using a test data set.

METHODS

An in-depth literature review was undertaken to identify the range of statistical tests used in the validation of quantitative food frequency questionnaires (QFFQs). Four databases were accessed to search for statistical methods and interpretation criteria used in papers focusing on relative validity. The identified tests and interpretation criteria were applied to a data set obtained using a QFFQ and four repeated 24-hour recalls from 47 adults (18-65 years) residing in rural Eastern Cape, South Africa.

RESULTS

102 studies were screened and 60 were included. Six statistical tests were identified; five with one set of interpretation criteria and one with two sets of criteria, resulting in seven possible validity interpretation outcomes. Twenty-one different combinations of these tests were identified, with the majority including three or less tests. Coefficient of correlation was the most commonly used (as a single test or in combination with one or more tests). Results of our application and interpretation of multiple statistical tests to assess validity of energy, macronutrients and selected micronutrients estimates illustrate that for most of the nutrients considered, some outcomes support validity, while others do not.

CONCLUSIONS

One to three statistical tests may not be sufficient to provide comprehensive insights into various facets of validity. Results of our application and interpretation of multiple statistical tests support the value of such an approach in gaining comprehensive insights in different facets of validity. These insights should be considered in the formulation of conclusions regarding validity to answer a particular dietary intake related research question.

The Effect of BCMO1 Gene Variants on Macular Pigment Optical Density in Young Healthy Caucasians

Background: Serum lutein (L) and zeaxanthin (Z) positively correlate with macular pigment optical density (MPOD); hence, the latter is a valuable indirect tool for measuring L and Z content in the macula. L and Z have been attributed antioxidant capacity and protection from certain retinal diseases but their uptake within the eye is thought to depend on genetic, age, and environmental factors. In particular, gene variants within beta-carotene monooxygenase (BCMO1) are thought to modulate MPOD in the macula.

Objectives: To determine the effect of BCMO1 single nucleotide polymorphisms (SNPs) rs11645428, rs6420424, and rs6564851 on MPOD in a cohort of young healthy participants of Caucasian origin with normal ocular health.

Design: In this cohort study, MPOD was assessed in 46 healthy participants (22 male and 24 female) with a mean age of 23.8 ± 4.0 years (range 19–33). The three SNPs, rs11645428, rs6420424, rs6564851 that have established associations with MPOD were determined using MassEXTEND (hME) Sequenom assay. One-way analysis of variance was performed on groups segregated into homozygous and heterozygous BCMO1 genotypes. Correlations between body mass index (BMI), iris color, gender, central retinal thickness (CRT), diet, and MPOD were investigated.

Results: Macular pigment optical density neither significantly varied with BCMO1 rs11645428 (F_2,41 = 0.70, p = 0.503), rs6420424 (F_2,41 = 0.21, p = 0.801) nor rs6464851 homozygous or heterozygous genotypes (F_2,41 = 0,13, p = 0.88), in this young healthy cohort. The combination of these three SNPs into triple genotypes based on plasma conversion efficiency did not affect MPOD (F_2,41 = 0.07, p = 0.9). There was a significant negative correlation with MPOD and CRT (r = −0.39, p = 0.01) but no significant correlation between BMI, iris color, gender, and MPOD.

Conclusion: Our results indicate that macular pigment deposition within the central retina is not dependent on BCMO1 gene variants in young healthy people. We propose that MPOD is saturated in younger persons and/or other gene variant combinations determine its deposition.

Assessment of the iodine status of the Wa national boarding school students in Southwest China

Iodine deficiency disorder (IDD) has been recognized as a major public health problem worldwide and has serious detrimental effects on the growth and development of the children. Therefore, monitoring the iodine status of the school-aged children is of great importance. We randomly recruited 159 boarding school students (aged from 6 to 14) from 10 primary schools in Lincang County, Yunnan Province. The dietary iodine level of the students was measured by the new mixed meal method and chemical analysis. Fifty-seven daily water samples and 32 salt samples were collected from the same surveyed area to determine the iodine content using the sulfate cerium catalytic spectrophotometric method and the hyposulphite quantitative titration method, respectively. The iodine level of each water sample was ranged from 0.611 to 1.473 μg/L. The median and the mean value of the iodine content in water were 0.972 and 0.979 ± 0.189 μg/L. The average iodine intake of each age group was higher that the recommended nutrient intakes (RNI) but lower than the tolerable upper intake level (UL). The median and the mean value of the iodine content in salt were 25.53 and 25.62 ± 1.70 mg/kg. Taken together, the present study investigated the iodine intake status of Wa school-aged children through examination of their dietary iodine intake, the environment, and the salt iodine status. Results showed that the status of the iodine uptake of the Wa children were higher than the RNI, but lower than the UL.