Reproducibility of a web-based FFQ for 13- to 15-year-old Danish adolescents

Food & Fertility Study: study protocol for a Danish multicentre prospective cohort study investigating the association between food intake and semen quality, pregnancy and birth outcomes in infertile women and men

INTRODUCTION

Worldwide infertility is highly prevalent, and lifestyle factors, such as food intake, could have an essential role in the success of a fertility treatment. The literature is not consistent and adequate for recommendations to the increasing number of women and men of reproductive age who ask for lifestyle guidance. Therefore, the aims of the Food & Fertility Study will be to investigate the possible association between food intake and semen quality in men, and pregnancy and live birth rates in women undergoing intrauterine insemination or assisted reproductive technology treatment.

METHODS AND ANALYSIS

The Food & Fertility Study is a multicentre prospective cohort study which plans to enrol a total of 4000 women and men between 2022 and 2024. Data collection will take place in four fertility clinics through a web-based Food Frequency Questionnaire. Data on sperm quality and pregnancy and live birth rates will be obtained from medical records and national registers.

ETHICS AND DISSEMINATION

The study is registered with and approved by the Danish Data Protection Agency, the North Denmark Region (j.nr: 2019-055298). Further, a Statement of Work and a Master Collaboration Agreement have been submitted and approved by the regional legal departments (AGR-2019-731-9667). Dissemination of the results will be through national and international conferences, in scientific environments, in the form of lectures to the broader public, and by peer-reviewed publications in international scientific journals.

TRIAL REGISTRATION NUMBER

NCT05454046.

A meta-analysis of the reproducibility of food frequency questionnaires in nutritional epidemiological studies

BACKGROUND

Reproducibility of FFQs measures the consistency of the same subject at different time points. We performed a meta-analysis to explore the reproducibility of FFQs and factors related to reproducibility of FFQs.

METHODS AND FINDINGS

A systematic literature review was performed before July 2020 using PubMed and Web of Science databases. Pooled intraclass and Spearman correlation coefficients (95% confidence interval) were calculated to assess the reproducibility of FFQs. Subgroup analyses based on characteristics of study populations, FFQs, or study design were performed to investigate factors related to the reproducibility of FFQs. A total of 123 studies comprising 20,542 participants were eligible for the meta-analysis. The pooled crude intraclass correlation coefficients ranged from 0.499 to 0.803 and 0.499 to 0.723 for macronutrients and micronutrients, respectively. Energy-adjusted intraclass correlation coefficients ranged from 0.420 to 0.803 and 0.507 to 0.712 for macronutrients and micronutrients, respectively. The pooled crude and energy-adjusted Spearman correlation coefficients ranged from 0.548 to 0.851 and 0.441 to 0.793, respectively, for macronutrients; and from 0.573 to 0.828 and 0.510 to 0.744, respectively, for micronutrients. FFQs with more food items, 12 months as dietary recall interval (compared to less than 12 months), and a shorter time period between repeated FFQs resulted in superior FFQ reproducibility.

CONCLUSIONS

In conclusion, FFQs with correlation coefficients greater than 0.5 for most nutrients may be considered a reliable tool to measure dietary intake. To develop FFQs with higher reproducibility, the number of food items and dietary recall interval should be taken into consideration.

Reproducibility of a Short-Form, Multicomponent Dietary Questionnaire to Assess Food Frequency Consumption, Nutrition Knowledge, and Lifestyle (SF-FFQ4PolishChildren) in Polish Children and Adolescents

The aim of the study was to assess the reproducibility of a short-form, multicomponent dietary questionnaire (SF-FFQ4PolishChildren) in Polish children and adolescents. The study involved 437 children (6–10 years old) and 630 adolescents (11–15 years old) from rural and urban areas of Poland. The self-administered questionnaire was related to nutrition knowledge, dietary habits, active/sedentary lifestyle, self-reported weight and height, and socioeconomic data. The questionnaire was completed with a two-week interval—twice by parents for their children (test and retest for children), twice by adolescents themselves (adolescent’s test and retest) and once by adolescents’ parents (parent’s test). The strength of agreement measured using the kappa statistic was interpreted as follows: 0–0.20 slight, 0.21–0.40 fair, 0.41–0.60 moderate, 0.61–0.80 good, and 0.81–1.00 excellent. Regarding the frequency of consumption of food items and meals, kappa statistics were 0.46–0.81 (the lowest: fruit/mixed fruit and vegetable juices; the highest: Energy drinks) in test–retest for children, 0.30–0.54 (fruit/mixed fruit and vegetable juices; breakfast, respectively) in adolescent’s test–retest, 0.27–0.56 (the lowest: Sweets, fruit, dairy products; the highest: Breakfast) in adolescent’s test and parent’s test. Lower kappa statistics were found for more frequently consumed foods (juices, fruit, vegetables), higher kappa statistics were found for rarely consumed foods (energy drinks, fast food). Across study groups, kappa statistics for diet quality scores were 0.31–0.55 (pro-healthy diet index, pHDI) and 0.26–0.45 (non-healthy diet index, nHDI), for active/sedentary lifestyle items they were 0.31–0.72, for components of the Family Affluence Scale (FAS) they were 0.55–0.93, for BMI categories (based on self-reported weight and height) they were 0.64–0.67, for the nutrition knowledge (NK) of adolescents the kappa was 0.36, for the nutrition knowledge of children’s parents it was 0.62. The Spearman’s correlations for diet quality scores were 0.52–0.76 (pHDI) and 0.53–0.83 (nHDI), for screen time score they were 0.45–0.78, for physical activity score they were 0.51–0.77, for the FAS score they were 0.90–0.93, and for the NK score they were 0.68–0.80. The questionnaire can be recommended to evaluate dietary and lifestyle behaviors among children and adolescents.

Reproducibility of A Non-Quantitative Food Frequency Questionnaire (62-Item FFQ-6) and PCA-Driven Dietary Pattern Identification in 13-21-Year-Old Females

The aim of this study was to evaluate the test-retest reproducibility of a non-quantitative food frequency questionnaire (acronym: 62-item FFQ-6) and the possibility of identifying dietary patterns (DPs) in 13-21-year-old females. The study involved 97 females within three age groups: 13-15, 16-18, and 19-21 years, including 31, 38, and 28 subjects, respectively. The questionnaire was completed twice with a two-week interval (test and retest). For the total sample, using a principal component analysis (PCA), two similar PCA-driven DPs (DP1 and DP2) were identified separately from test data and retest data, considering two sets of input variables. 60-item-DP1 and 60-item-DP2 were identified after excluding two items-vegetables and fruits in general-due to including single items of various kinds of vegetables and fruits. After an aggregation of some items of the questionnaire, 25-item-DP1 and 25-item-DP2 were identified. The kappa statistic (test vs. retest) in the total sample averaged at 0.52 (0.32-0.72 for food items), while within age groups, it averaged at 0.41, 0.53, and 0.65, respectively. The percentage of subjects classified into the same food frequency category (test vs. retest) in the total sample averaged at 68% (51%-89% for food items), while within age groups, it averaged at 60%, 68%, and 77%, respectively. The Spearman correlations between dietary pattern scores (test vs. retest) in the total sample were: 0.84 (within age groups 0.83, 0.81, and 0.78, respectively) for 60-item-DP1, 0.68 (within age groups 0.24, 0.79, and 0.76, respectively) for 60-item-DP2, 0.76 (within age groups 0.56, 0.82, and 0.89, respectively) for 25-item-DP1, and 0.48 (within age groups 0.40, 0.57, and 0.53, respectively) for 25-item-DP2 (p < 0.05 for all). In conclusion, the test-retest reproducibility of the 62-item FFQ-6 was good or very good for most food items, with a tendency to be higher in older age groups of females under study. Due to the acceptable-to-good reproducibility of dietary pattern identification, the use of a 62-item FFQ-6 to describe the overall diet of young Polish females can be recommended.

Reproducibility of a Questionnaire for Dietary Habits, Lifestyle and Nutrition Knowledge Assessment (KomPAN) in Polish Adolescents and Adults

The aim of the study was to evaluate the reproducibility of the Dietary Habits and Nutrition Beliefs Questionnaire (KomPAN) in Polish adolescents and adults, including the assessment of indexes developed based on the questionnaire. In total, the study involved 954 subjects aged 15–65 (53.9% females). Interviews using the interviewer-administered questionnaire (IA-Q) in healthy subjects (n 299) and the self-administered questionnaire (SA-Q) in healthy subjects (n 517) and outpatients (n 138) were conducted and repeated after two weeks. Considering the consumption frequency of 33 food items, the cross-classification (test-retest) agreement of classification into the same category obtained for IA-Q in healthy subjects ranged from 72.2% (fruit juices) to 91.6% (energy drinks); the kappa statistic was >0.60 for all food items. For SA-Q conducted in healthy subjects the cross-classification agreement ranged from 63.8% (vegetable oils, margarines, mixes of butter and margarines) to 84.7% (lard); the kappa statistic was >0.50 for all food items. For SA-Q in outpatients, the cross-classification agreement ranged from 42.0% (both fruit juices and white rice, white pasta, fine-ground groats) to 92.0% (energy drinks); the kappa statistic was ≥0.40 for 20/33 food items. The kappa statistic for lifestyle items ranged 0.42–0.96, and for the nutrition knowledge level it ranged 0.46–0.73. The questionnaire showed moderate to very good reproducibility and can be recommended to assess dietary habits, lifestyle and nutrition knowledge of healthy adolescents and adults and those suffering from chronic diseases, after validation and/or calibration study is carried out. The reproducibility of the interviewer-administered questionnaire was better than its self-administered version. The reproducibility of the self-administered questionnaire was better in healthy subjects than in outpatients.

Being born small-for-gestational-age is associated with an unfavourable dietary intake in Danish adolescent girls: findings from the Danish National Birth Cohort

Individuals born small have an increased risk for developing type 2 diabetes. Altered food preferences in these subjects seem to play a role; however, limited evidence is available on the association between being born small-for-gestational-age (SGA) at term and food intake in adolescence. Alterations in leptin, ghrelin and dopamine levels are suggested mechanisms linking SGA with later food intake. From a large prospective Danish National Birth Cohort, we compared dietary intake of adolescents being born SGA with normal-for-gestational-age (NGA) adolescents. Intake of foods and nutrients was assessed by a validated food frequency questionnaire in a subsample of 15,607 14-year-old individuals born at term. SGA was defined by birth weight (BW) &lt;10th percentile (n = 1470) and NGA as BW between 10 and 90th percentile (n = 14,137) according to sex and gestational age-specific BW standard curves. Girls born SGA had a 7% (95% CI: 3-12%, P = 0.002) higher intake of added sugar and a 2-8% lower intake of dietary fibre, vegetables, polyunsaturated fatty acids, and total n-6, compared with NGA girls (P &lt; 0.05). Adjusting for parental socio-occupational status, maternal smoking and diet in pregnancy did not substantially change the differences in dietary intake, except from dietary fibre, which were no longer statistically significant. No significant differences in dietary intake between SGA and NGA boys were found. In summary, girls born SGA had an unfavourable dietary intake compared with NGA girls. These differences persisted after controlling for potential confounders, thus supporting a fetal programming effect on dietary intake in girls born SGA at term. However, residual confounding by other factors operating early in childhood cannot be excluded.

Relative validity of a web-based food frequency questionnaire for Danish adolescents

Background

With increased focus on dietary intake among youth and risk of diseases later in life, it is of importance, prior to assessing diet-disease relationships, to examine the validity of the dietary assessment tool. This study’s objective was to evaluate the relative validity of a self-administered web-based FFQ among Danish children aged 12 to 15 years.

Methods

From a nested sub-cohort within the Danish National Birth Cohort, 124 adolescents participated. Four weeks after completion of the FFQ, adolescents were invited to complete three telephone-based 24HRs; administered 4 weeks apart. Mean or median intakes of nutrients and food groups estimated from the FFQ were compared with the mean of 3x24HRs. To assess the level of ranking we calculated the proportion of correctly classified into the same quartile, and the proportion of misclassified (into the opposite quartile). Spearman’s correlation coefficients and de-attenuated coefficients were calculated to assess agreement between the FFQ and 24HRs.

Results

The mean percentage of all food groups, for adolescents classified into the same and opposite quartile was 35 and 7.5%, respectively. Mean Spearman’s correlation was 0.28 for food groups and 0.35 for nutrients, respectively. Adjustment for energy and within-person variation in the 24HRs had little effect on the magnitude of the correlations for food groups and nutrients. We found overestimation by the FFQ compared with the 24HRs for fish, fruits, vegetables, oils and dressing and underestimation by the FFQ for meat/poultry and sweets. Median intake of beverages, dairy, bread, cereals, the mean total energy and carbohydrate intake did not differ significantly between the two methods.

Conclusion

The relative validity of the FFQ compared with the 3x24HRs showed that the ranking ability differed across food groups and nutrients with best ranking for estimated intake of dairy, fruits, and oils and dressing. Larger variation was observed for fish, sweets and vegetables. For nutrients, the ranking ability was acceptable for fatty acids and iron. When evaluating estimates from the FFQ among Danish adolescents these findings should be considered.

Electronic supplementary material

The online version of this article (10.1186/s12937-018-0312-7) contains supplementary material, which is available to authorized users.

Maternal fish oil supplementation during lactation is associated with reduced height at 13 years of age and higher blood pressure in boys only

Dietary long-chain n-3 PUFA (n-3 LCPUFA) in infancy may have long-term effects on lifestyle disease risk. The present follow-up study investigated whether maternal fish oil (FO) supplementation during lactation affected growth and blood pressure in adolescents and whether the effects differed between boys and girls. Mother-infant pairs (n 103) completed a randomised controlled trial with FO (1·5 g/d n-3 LCPUFA) or olive oil (OO) supplements during the first 4 months of lactation; forty-seven mother-infant pairs with high fish intake were followed-up for 4 months as the reference group. We also followed-up 100 children with assessment of growth, blood pressure, diet by FFQ and physical activity by 7-d accelerometry at 13·5 (sd 0·4) years of age. Dried whole-blood fatty acid composition was analysed in a subgroup (n 49). At 13 years of age, whole-blood n-3 LCPUFA, diet, physical activity and body composition did not differ between the three groups. The children from the FO group were 3·4 (95 % CI 0·2, 6·6) cm shorter (P=0·035) than those from the OO group, and tended to have less advanced puberty (P=0·068), which explained the difference in height. There was a sex-specific effect on diastolic blood pressure (P sex×group=0·020), which was driven by a 3·9 (95 % CI 0·2, 7·5) mmHg higher diastolic blood pressure in the FO compared with the OO group among boys only (P=0·041). Our results indicate that early n-3 LCPUFA intake may reduce height in early adolescence due to a delay in pubertal maturation and increase blood pressure specifically in boys, thereby tending to counteract existing sex differences.

A Diet Score Assessing Norwegian Adolescents' Adherence to Dietary Recommendations-Development and Test-Retest Reproducibility of the Score

Assessment of adolescents’ dietary habits is challenging. Reliable instruments to monitor dietary trends are required to promote healthier behaviours in this group. The purpose of this cross-sectional study was to assess adolescents’ adherence to Norwegian dietary recommendations with a diet score and to report results from, and test-retest reliability of, the score. The diet score involved seven food groups and one physical activity indicator, and was applied to answers from a semi-quantitative food frequency questionnaire (FFQ) administered twice. Reproducibility of the score was assessed with Cohen’s Kappa (κ statistics) at an interval of three months. The setting was eight lower-secondary schools in Hordaland County, Norway, and subjects were adolescents (n = 472) aged 14–15 years and their caregivers. Results showed that the proportion of adolescents consistently classified by the diet score was 87.6% (κ = 0.465). For food groups, proportions ranged from 74.0% to 91.6% (κ = 0.249 to κ = 0.573). Less than 40% of the participants were found to adhere to recommendations for frequencies of eating fruits, vegetables, added sugar, and fish. Highest compliance to recommendations was seen for choosing water as beverage and limit the intake of red meat. The score was associated with parental socioeconomic status. The diet score was found to be reproducible at an acceptable level. Health promoting work targeting adolescents should emphasize to increase the intake of recommended foods to approach nutritional guidelines.