Relative validity of a food frequency questionnaire to assess nutrient intake in pregnant women

Evaluating Validated Diet Quality Indices Used in Pregnant Women in High-Income Countries: A Systematic Review

CONTEXT

Diet quality indices (DQIs) assess the level of adherence to dietary recommendations and a specified dietary pattern in populations; however, there is limited evidence regarding the construct criteria and validation methodology of DQIs used in pregnant women.

OBJECTIVES

The objectives of this study were to (i) identify and describe characteristics of DQIs that have been validated for use in pregnant women in high-income countries, and (ii) evaluate criteria used to develop DQIs and validation methodologies employed.

DATA SOURCES

CINAHL, Embase, Medline, SCOPUS, and Web of Science were systematically searched for eligible articles published between 1980 and November 2022 that focused on DQIs validated for use in pregnant women from high-income countries.

DATA EXTRACTION

Characteristics, development criteria, and validation methodologies used in the included articles were extracted by one reviewer and checked by a second reviewer.

DATA ANALYSIS

A narrative synthesis and descriptive statistics were used to summarize the review findings. Reporting was guided by the Preferred Reporting Items for Systematic Reviews and Meta-analyses statement.

RESULTS

Six articles with 5 validated DQIs were identified. In total, 3777 participants were included - five articles had pregnant women aged 31-50 years and in their second trimester. Food frequency questionnaires were used as the dietary assessment method in all studies, and 3 DQIs were used to assess dietary intake at 1 time point, using 2 different dietary assessment methods. No indices fulfilled preferred features for the DQI development criteria developed by Burggraf et al (2018). Construct validity was assessed by all DQIs, followed by criterion validity (n = 4) and test-retest reliability (n = 2).

CONCLUSION

Limited high-quality validated DQIs for use in pregnant women in high-income countries were identified. Scoring for DQI components were not specific to nutrient requirements for pregnant women. Findings from this review may inform the development of DQIs that evaluate specific dietary requirements and specific food safety considerations applicable to pregnancy.

SYSTEMATIC REVIEW REGISTRATION

https://osf.io/u2hrq.

Assessing the reproducibility and validity of a food frequency questionnaire for pregnant women from the Chinese Miao ethnic group

Background

Currently, no food frequency questionnaire is available to be administered exclusively to ethnic minorities in China. This study aimed to evaluate the reproducibility and validity of a culturally tailored semi-quantitative food frequency questionnaire (FFQ) designed for pregnant women belonging to the Miao ethnic group in China.

Methods

A total of 74 questions in the FFQ were administered to collect dietary information from Miao women in China during their pregnancy. This study included 153 and 127 pregnant women, respectively, for testing the validity and reproducibility of the results. Baseline FFQ data (FFQ1) were collected initially, followed by the administration of a repeated FFQ 4-6 weeks later (FFQ2). Two 24-h recalls (24HR) were used as references to compare food groups and nutrient intake. Pearson/Spearman's coefficients were used to measure the validity and reproducibility of the FFQ. Quartile cross-classification, weighted kappa coefficients, and Bland-Altman plots were employed to assess the agreement.

Results

Most food groups and nutrient intake estimated by the FFQ were higher than those estimated by the 24HR. Food groups and nutrients' correlations for FFQ vs. 24HR after being energy-adjusted and de-attenuated, respectively, were 0.10 (vegetables) to 0.45 (grains/tubers) and 0.15 (iron) to 0.52 (riboflavin). Comparatively, correlation coefficients for FFQ1 vs. FFQ2 ranged from 0.41 (fruit) to 0.71 (vegetables) and from 0.45 (energy) to 0.64 (calcium). The percentage of pregnant women classified in the same or adjacent quartiles ranged from 64.08% (vegetables) to 95.29% (sour soup) and from 68.88% (vitamin E) to 78.81% (energy). Weighted kappa coefficients exceeded 0.2 for food groups and most nutrients, and Bland-Altman plots demonstrated acceptable agreement between the two tools.

Conclusions

This study provides novel information on the validation of FFQ. It demonstrates that the FFQ exhibits ideal reproducibility and acceptable validity in estimating and ranking the intake of food groups and most nutrients among pregnant women belonging to the Chinese Miao ethnic group.

Maternal macronutrient and energy intake during pregnancy: a systematic review and meta-analysis

BACKGROUND

Nutritional status during pregnancy can have a significant impact on infant and maternal health outcomes. To maintain maternal homeostasis and support fetal growth, adequate macronutrient and energy intake during pregnancy is essential. Therefore, this study sought to systematically review and meta-analyze macronutrient and energy intakes during pregnancy.

METHODS

A systematic review and meta-analysis was carried out based on the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. The required data were collected from four databases including: Web of Sciences, ProQuest, Scopus, and PubMed, from 1 January 1980 to 30 May 2023, by using a combination of search terms (dietary pattern" OR "diet quality" OR "food habits" OR "nutrition surveys" OR "diet surveys" OR "food-frequency questionnaire" OR "diet record" OR "dietary recall") AND ( "pregnancy" OR "reproduction" OR "maternal health" OR "neonatal outcomes") among interventional and observational studies. Excel and STATA version 11 were used for data analysis.

RESULTS

Among 7081 published articles, 54 studies were included in the review. Most of the 33 (61%) studies were cohort studies and a total of 135,566 pregnant women were included. The overall average of energy, carbohydrate, fat, and protein intake was 2036.10 kcal/day, 262.17 gr/day, 74.17 gr/day, and 78.21 gr/day, respectively. Also, energy intake during pregnancy was higher in American (2228.31 kcal/day, CI95%: 2135.06-2325.63) and Eastern Mediterranean regions (2226.70 kcal/day, CI95%: 2077.23-2386.92) than other regions (P < 0.001). Energy intake was higher in the third trimester than others (2115.64 kcal/day, CI95%: 1974.15-2267.27). Furthermore, based on the findings, there was a significant difference between energy intake in different World Health Organization (WHO) regions (P < 0.05).

CONCLUSIONS

According to the results of meta-analysis, the average total energy was below than average total energy required during pregnancy. More efforts are needed to encourage women to adopt healthy eating habits during pregnancy to support healthy fetal and infant development.

The relative validity of a semiquantitative food frequency questionnaire among pregnant women in the United Arab Emirates: The Mutaba'ah study

Background: Food frequency questionnaire (FFQ) is the most frequently used dietary assessment method in estimating dietary intakes in epidemiological studies. Aim: This study aimed to assess the relative validity of a semiquantitative FFQ in evaluating dietary intake among pregnant women in the United Arab Emirates. Methods: Within the Mutaba'ah study, a subsample of 111 pregnant women completed a semiquantitative FFQ and a single 24-hour dietary recall (24-HDR) regarded as the reference method. Absolute and energy-adjusted nutrient and food intakes between the FFQ and 24-HDR were compared using the Wilcoxon signed ranks test, correlations, Bland-Altman analysis, cross-classification, and weighted kappa analysis. Results: There were no significant differences in reported absolute intakes between the FFQ and 24-HDR for carbohydrates, whole grains, white meat, beta-carotene, vitamin K, sodium, and selenium. Spearman's correlation coefficients between the FFQ and 24-HDR ranged from 0.09 (trans fatty acids) to 0.5 (potassium) for absolute intakes. Correlation decreased after energy adjustment. Bland-Altman analysis showed that the FFQ overestimated intakes compared with 24-HDR and that the limits of agreement were wide. The average percentage of pregnant women classified into the same or adjacent quartile of intake by both methods was 73%. Weighted kappa values ranged from -0.02 (white meat) to 0.33 (magnesium). Conclusion: Our findings showed that the semi-quantitative FFQ is a useful tool in ranking pregnant women from the Emirati population according to their dietary intake. However, the validity of some estimated intakes was poor; hence, certain intakes should be interpreted with caution.

Application of machine learning algorithm for predicting gestational diabetes mellitus in early pregnancy†

Objective

To study the application of a machine learning algorithm for predicting gestational diabetes mellitus (GDM) in early pregnancy.

Methods

This study identified indicators related to GDM through a literature review and expert discussion. Pregnant women who had attended medical institutions for an antenatal examination from November 2017 to August 2018 were selected for analysis, and the collected indicators were retrospectively analyzed. Based on Python, the indicators were classified and modeled using a random forest regression algorithm, and the performance of the prediction model was analyzed.

Results

We obtained 4806 analyzable data from 1625 pregnant women. Among these, 3265 samples with all 67 indicators were used to establish data set F1; 4806 samples with 38 identical indicators were used to establish data set F2. Each of F1 and F2 was used for training the random forest algorithm. The overall predictive accuracy of the F1 model was 93.10%, area under the receiver operating characteristic curve (AUC) was 0.66, and the predictive accuracy of GDM-positive cases was 37.10%. The corresponding values for the F2 model were 88.70%, 0.87, and 79.44%. The results thus showed that the F2 prediction model performed better than the F1 model. To explore the impact of sacrificial indicators on GDM prediction, the F3 data set was established using 3265 samples (F1) with 38 indicators (F2). After training, the overall predictive accuracy of the F3 model was 91.60%, AUC was 0.58, and the predictive accuracy of positive cases was 15.85%.

Conclusions

In this study, a model for predicting GDM with several input variables (e.g., physical examination, past history, personal history, family history, and laboratory indicators) was established using a random forest regression algorithm. The trained prediction model exhibited a good performance and is valuable as a reference for predicting GDM in women at an early stage of pregnancy. In addition, there are certain requirements for the proportions of negative and positive cases in sample data sets when the random forest algorithm is applied to the early prediction of GDM.

Reliability and Concurrent and Construct Validity of a Food Frequency Questionnaire for Pregnant Women at High Risk to Develop Fetal Growth Restriction

Accuracy of dietary assessment instruments such as food frequency questionnaire (FFQ) is crucial in the evaluation of diet–disease relationships. Test–retest reliability and concurrent and construct validity of a FFQ were evaluated in 150 pregnant women at high risk to develop fetal growth restriction randomly selected from those included in the improving mothers for better prenatal care trial Barcelona (IMPACT BCN). The FFQ and dietary records were performed at baseline and 34–36 weeks of gestation. Test–retest reliability of the FFQ for 12 food groups and 17 nutrients was moderate (ICC = 0.55) and good (ICC = 0.60), respectively. Concurrent validity between food, nutrients and a composite Mediterranean diet score (MedDiet score) and food records was fair for foods and nutrients (ρ average = 0.38 and 0.32, respectively) and moderate (r = 0.46) for the MedDiet score. Validation with biological markers ranged from poor (r = 0.07) for olives to moderate (r = 0.41) for nuts. A fair concordance between methods were found for nutrients (weighted κ = 0.22) and foods (weighted κ = 0.27). The FFQ-derived MedDiet score correlated in anticipated directions with intakes of nutrients and foods derived by food records. The FFQ showed a moderate test–retest reliability and reasonable validity to rank women according to their food and nutrient consumption and adherence to the Mediterranean diet.

Development and validation of the semi-quantitative brief food frequency questionnaire to assess the magnesium intake in young women

AIM

The aim of the study was to develop and validate the semi-quantitative brief food frequency questionnaire to assess the magnesium intake (Mg-FFQ).

METHODS

The developed questionnaire consists of 39 questions and it was validated in a group of 75 women aged 20-30. The validity was assessed with reference to the 3-day dietary record and the reproducibility was assessed for a period of 6 weeks.

RESULTS

The Bland-Altman index for the assessment of validity was 6.7% and for reproducibility-8.0%, while the kappa statistic indicated a slight and substantial agreement, respectively. The high reproducibility was confirmed by a high share of respondents correctly classified into tertiles (73.3%) and correctly classified into categories of adequate/inadequate intake (85.3%).

CONCLUSION

For the developed and validated Mg-FFQ, a high reproducibility, accompanied by a satisfactory validity, was confirmed, so it may be used to assess the magnesium intake in the epidemiological studies in young Polish women aged 20-30.

The relationship between early pregnancy dietary intakes and subsequent birthweight and neonatal adiposity

Background

Maternal nutrition intakes may influence neonatal birthweight and adiposity; however, inconsistencies within the literature exist. The relationships between maternal dietary intakes in early pregnancy and both birthweight and neonatal adiposity requires elucidation. This study examined the relationship between early pregnancy dietary intakes and subsequent birthweight and neonatal adiposity.

Methods

Women were recruited at their convenience after sonographic confirmation of a singleton pregnancy. Women completed a Willet food frequency questionnaire evaluating habitual food and nutrient intakes at their first antenatal visit. Neonatal body composition was measured using air-displacement plethysmography.

Results

Of the 385 mother-neonate dyads, mean maternal age was 30.8 ± 5.3 years, mean Body Mass Index (BMI) was 24.5 ± 4.8 kg/m2 and 41.8% (n = 161) were nulliparous. There were no relationships between maternal food intakes and birthweight (P > 0.05) (n = 385). On multivariable analysis there was a positive relationship between polyunsaturated fat and neonatal fat mass index (FMI) (beta = 0.015, 95% CI = 0.002-0.028, P = 0.04) (n = 80).

Conclusion

Dietary intakes of polyunsaturated fat in early pregnancy are positively associated with neonatal FMI at birth on multivariable analysis. Further longitudinal studies need to explore this association and the long-term implications for the neonate.

Dietary Predictors of Phthalate and Bisphenol Exposures in Pregnant Women

Endocrine disrupting chemicals (EDCs) can disrupt fetal developmental processes during pregnancy, leading to long-term adverse outcomes in humans. A major source of exposure to EDCs, such as phthalates and bisphenols, is the food supply, primarily due to contamination from processing and packaging. Therefore, this review aimed to 1) review food-monitoring sources of phthalates and bisphenols, and 2) evaluate methodologies and provide future directions needed to establish EDC-limiting dietary recommendations in pregnancy. Using PubMed, 10 peer-reviewed studies were found on dietary predictors of EDC exposure in pregnancy, and all were selected for review. Use of plastic containers in pregnancy was associated with higher urinary phthalate metabolites, whereas canned food consumption was associated with higher urinary bisphenol A (BPA) concentrations. Foods and dietary patterns associated with healthier food choices (e.g., organic/grown/raised/caught foods, folic acid supplements, vegetarianism) were generally associated with lower urinary phthalate metabolite and BPA concentrations. Despite the many food-monitoring studies reporting high BPA and phthalate concentrations in various foods, the designs of most studies described here were not sufficiently robust to consistently detect associations of specific foods/food groups with phthalates and BPA. Given the limitations of currently available research, future studies should incorporate more valid questionnaires to accurately assess dietary EDC exposure, strive for concurrent diet and exposure assessment, and assess whether geographical and cultural differences modify associations of diet with gestational EDC exposures. Such progress will be critical for developing dietary recommendations that ensure the safety and health of pregnant women.

Maternal nutrient intakes from food and drinks consumed in early pregnancy in Ireland

Background

The aim of this observational study was to measure food, macronutrient and micronutrient intakes of women presenting for antenatal care and assess compliance with current nutritional recommendations.

Methods

Women were recruited in the first trimester of pregnancy. Maternal weight and height were measured and body mass index (BMI) calculated. Body composition was measured using bioelectrical impedance analysis. Maternal energy and nutrient intakes were estimated using a validated Willett Food Frequency Questionnaire and misreporting of energy intakes (EI) determined.

Results

Plausible EIs were reported in 402 women. Mean age, weight and BMI were 30.8 years, 67.1 kg and 24.6 kg/m2 respectively. Median EIs were 2111 kcal, and median protein, carbohydrate and fat intakes were 17.3, 48.1 and 36.2 g/MJ/day, respectively. More than 90% of women exceeded the recommended daily allowance for saturated fat. Nearly all of the women (99%) did not meet estimated average requirements (EAR) for vitamin D. One in three women failed to achieve a dietary folate intake of 400 µg/day. Over one in five women failed to meet the EAR for iron, and 14% failed to achieve the EAR for calcium.

Conclusions

Our findings highlight concerning deficits in nutrient intakes among women and will help guide professional dietary advice to women attending for future obstetric care in Ireland.

The Impact of Maternal Eating Disorders on Dietary Intake and Eating Patterns during Pregnancy: A Systematic Review

Maternal nutrition in pregnancy has a key influence on optimum fetal health. Eating disorders (EDs) during pregnancy may have detrimental effects on fetal growth and the child’s early development. There is limited knowledge concerning the eating behavior, dietary intake and derived nutritional biomarkers as well as the nutrient supplementation in women with EDs during pregnancy. We performed a systematic review according to the PRISMA statement to synthesize current evidence in this field. Of N = 1203 hits, 13 full-texts were included in the qualitative synthesis. While women with current Binge Eating Disorder (BED) showed higher energy and fat intakes during pregnancy, women with a lifetime Anorexia Nervosa (AN), Bulimia Nervosa (BN) or both (AN + BN) had similar patterns of nutrient intake and dietary supplement use as healthy women. There is evidence, that women with a history of EDs have a sufficient diet quality and are more likely to be vegetarian. Dieting and bingeing improved substantially with pregnancy. The highlighted differences in the consumption of coffee/caffeine and artificially sweetened beverages as well as the elevated prevalence of iron deficiency anemia in women with a past or active ED during pregnancy might have an important impact on fetal development.

Maternal glycemic index and glycemic load in pregnancy and offspring metabolic health in childhood and adolescence-a cohort study of 68,471 mother-offspring dyads from the Danish National Birth Cohort

BACKGROUND

High glycemic index (GI) and glycemic load (GL) as indicators of carbohydrate quality and quantity have been found to increase risk of metabolic outcomes in adults. Whether carbohydrate quality may influence metabolic programming already in early life is unknown. We examined the association of maternal GI and GL with offspring body mass index (BMI) in the first 7 years of life among 68,471 mother-offspring dyads from the Danish National Birth Cohort (DNBC). In a sub-cohort of offspring with clinical data (n = 1234) that included 608 dyads exposed to gestational diabetes mellitus (GDM), we also examined the relation to metabolic health at 9-16 years.

METHODS

Maternal GI and GL were quantified using a mid-pregnancy food frequency questionnaire. We used birth weight and length to calculate offspring's ponderal index. Age- and sex-specific BMI z scores at 5 mo, 12 mo, and 7 y were standardized against WHO reference data. In the clinical cohort, we quantified body composition, HOMA-IR, and HOMA-B. We used multivariable mixed linear and Poisson regression to model the associations.

RESULTS

Median (IQR) of GI and GL were 83 (63-111) and 241 (180-333) g/day, respectively. We found that GI (Q4 vs. Q1:1.09, 95%CI: 1.03, 1.15) and GL (Q4 vs. Q1:1.10, 95%CI: 1.05, 1.16) modestly increased the relative risk of large-for gestational age (LGA). In the clinical sub-cohort, we observed a potential increase in offspring HOMA-IR, adiposity, and metabolic syndrome z score with higher maternal GI and GI. These associations were stronger among the GDM-exposed offspring, but the CI included the null value.

CONCLUSION

We found associations of GI and GL in pregnancy with offspring LGA. Potential long-term benefits to offspring exposed to GDM need to be confirmed in larger, well-powered studies.

Development and Validation of a Mediterranean Oriented Culture-Specific Semi-Quantitative Food Frequency Questionnaire

The objectives were to develop a Mediterranean oriented semi-quantitative food frequency questionnaire (FFQ) and evaluate its validity in measuring energy and nutrient intakes. For FFQ development, the main challenge was to merge food items and practices reflecting cultural Mediterranean preferences with other food choices ensuing from diet transition to more westernized dietary patterns. FFQ validity was evaluated by comparing nutrient intakes against the average of two 24-h dietary recalls for 179 pregnant women. Although the mean intake values for most nutrients and energy tended to be higher when determined by the FFQ, the Cohen's d was below 0.3. Bland-Altman plots confirmed the agreement between the two methods. Positive significant correlations ranged from 0.35 to 0.77. The proportion of women classified correctly was between 73.2% and 92.2%, whereas gross misclassification was low. Weighted kappa values were between 0.31 and 0.78, while intraclass correlation coefficients were between 0.49 and 0.89. Our methodological approach for the development and validation of this FFQ provides reliable measurements of energy, macro- and micronutrient intakes. Overall, our culture-specific FFQ could serve as a useful assessment tool in studies aiming at monitoring dietary intakes, especially in the Mediterranean region, where countries share common cultural dietary habits.

Nutritional Epidemiology of Antenatal Smoking Cessation Among Japanese Women

This study compared the nutritional status before pregnancy, as well as dietary profiles and biomarkers during first trimester, between never-smokers and antenatal quitters among Japanese women. One hundred fifty pregnant women (79 never-smokers and 71 antenatal quitters) from two obstetrics and gynecology clinics were recruited in Japan. Subjects' prepregnancy nutritional status was indicated by their body mass index (BMI). In the first trimester, their dietary profiles were assessed by the Brief Diet-History Questionnaire (BDHQ) and pregnancy outcomes were screened by biomarker tests. Generalized linear regression was used to examine the differences of energy-adjusted dietary intakes and biomarker results between the two smoking groups, with adjustment of maternal age, BMI, gestation week, and parity. The results showed that antenatal quitters were more likely to have a prepregnancy underweight status than never-smokers. During the first trimester, antenatal quitters had significantly higher intakes of unsaturated fatty acids and antioxidants (vegetable lipids and isoflavone), and lower intakes of total cholesterol than never-smokers. Moreover, antenatal quitters had a significantly higher level of serum homocysteine (6.36 nmol/mL vs 4.88 nmol/mL) than never-smokers. In conclusion, antenatal quitters are more likely to have a poor nutritional status before pregnancy than never-smokers. Quitting smoking before pregnancy and having a good nutritional profile during the trimester may not sufficiently reverse the adverse effects of former smoking behaviors on pregnancy outcomes.

Use of a web-based dietary assessment tool in early pregnancy

BACKGROUND

Maternal diet is critical to fetal development and lifelong health outcomes. In this context, dietary quality indices in pregnancy should be explicitly underpinned by data correlating food intake patterns with nutrient intakes known to be important for gestation.

AIMS

Our aim was to assess the correlation between dietary quality scores derived from a novel online dietary assessment tool (DAT) and nutrient intake data derived from the previously validated Willett Food Frequency Questionnaire (WFFQ).

METHODS

524 women completed the validated semi-quantitive WFFQ and online DAT questionnaire in their first trimester. Spearman correlation and Kruskal-Wallis tests were used to test associations between energy-adjusted and energy-unadjusted nutrient intakes derived from the WFFQ, and diet and nutrition scores obtained from the DAT.

RESULTS

Positive correlations were observed between respondents' diet and nutrition scores derived from the online DAT, and their folate, vitamin B12, iron, calcium, zinc and iodine intakes/MJ of energy consumed derived from the WFFQ (all P < 0.001). Negative correlations were observed between participants' diet and nutrition scores and their total energy intake (P = 0.02), and their percentage energy from fat, saturated fat, and non-milk extrinsic sugars (NMES) (all P ≤ 0.001). Median dietary fibre, beta carotene, folate, vitamin C and vitamin D intakes derived from the WFFQ, generally increased across quartiles of diet and nutrition score (all P < 0.001).

CONCLUSIONS

Scores generated by this web-based DAT correlate with important nutrient intakes in pregnancy, supporting its use in estimating overall dietary quality among obstetric populations.

Maternal dietary patterns during pregnancy and offspring cardiometabolic health at age 6 years: The generation R study

BACKGROUND & AIMS

Maternal nutrition during pregnancy might be important in influencing offspring cardiometabolic health. However, research has focused mostly on specific nutrients or total energy, and possible effects of whole diet are unclear. We aimed to assess the associations between different dietary patterns during pregnancy and offspring cardiometabolic health among 2592 mother-child pairs from Generation R, a prospective population-based cohort study from fetal life onwards in Rotterdam, the Netherlands.

METHODS

Maternal diet was assessed in early pregnancy with a food-frequency questionnaire. We identified three a posteriori-dietary patterns, namely a 'Vegetable, fish and oil', 'Nuts, soy and high-fiber cereals' and 'Margarine, snacks and sugar'-pattern. An a priori-pattern was created based on the 'Dutch Healthy Diet Index'. Cardiometabolic health (pulse wave velocity, blood pressure, insulin, HDL-cholesterol and triglycerides) was measured at the child's age of 6 years.

RESULTS

In the crude models, the 'Vegetable, fish and oil', 'Nuts, soy and high-fiber cereals' and 'Dutch Healthy Diet Index' seemed beneficial, as higher adherence to these patterns was significantly associated with lower blood pressure and lower pulse wave velocity. After adjustment for other socio-demographic and lifestyle factors, most associations disappeared, except for lower pulse wave velocity with the 'Vegetable, fish and oil'-dietary pattern (-0.19 SD (95% CI -0.33; -0.06), highest quartile of adherence vs. lowest quartile). No associations were found between maternal dietary patterns and offspring blood lipids or insulin levels.

CONCLUSIONS

Our results suggest that there are no consistent independent associations of maternal dietary patterns with offspring cardiometabolic health at 6 years.

Reproducibility and relative validity of a semi-quantitative food frequency questionnaire for Chinese pregnant women

BACKGROUND

Food frequency questionnaire (FFQ) is a reliable tool to estimate dietary intake in large nutritional epidemiological studies, but there is lack of a current and validated FFQ for use in urban Chinese pregnant women. This study aimed to evaluate the reproducibility and validity of a semi-quantitative FFQ designed to estimate dietary intake among urban pregnant women in a cohort study conducted in central China.

METHODS

In the reproducibility study, a sample of 123 healthy pregnant women completed the first FFQ at 12-13 weeks gestation and the second FFQ 3-4 weeks later. To validate the FFQ, the pregnant women completed three 24-h recalls (24HRs) between the intervals of two FFQs.

RESULTS

The intraclass correlation coefficients of two administrations of FFQ for foods ranged from 0.23 (nuts) to 0.49 (fruits) and for nutrients from 0.24 (iodine) to 0.58 (selenium) and coefficients were all statistically significant. The unadjusted Pearson correlation coefficients between two methods ranged from 0.28 (beans) to 0.53 (fruits) for foods and from 0.15 (iodine) to 0.59 (protein) for nutrients. Energy-adjusted and de-attenuated correlation coefficients for foods ranged from 0.35 (beans) to 0.56 (fruits) and for nutrients from 0.11 (iodine) to 0.63 (protein), and all correlations being statistically significant except for iodine, sodium and riboflavin. On average, 67.0% (51.2%-80.5%) of women were classified by both methods into the same or adjacent quintiles based on their food intakes, while 68.5% (56.1%-77.2%) of women were classified as such based on nutrient intakes. Extreme misclassifications were very low for both foods (average of 2.0%) and nutrients (average of 2.2%). Bland-Altman Plots also showed reasonably acceptable agreement between two methods.

CONCLUSION

This FFQ is a reasonably reliable and valid tool for assessing most food and nutrient intakes of urban pregnant women in central China.

An estimation of periconceptional under-reporting of dietary energy intake

BACKGROUND

The purpose of this cross-sectional study was to examine periconceptional misreporting of energy intake (EI) using the Willet food frequency questionnaire (WFFQ).

METHODS

Women were recruited in the first trimester. Women completed a semi-quantitative WFFQ. Maternal body composition was measured using eight-electrode bioelectrical impedance analysis. Under-reporters were those whose ratio of EI to their calculated basal metabolic rate fell below the calculated plausible threshold for their physical activity category.

RESULTS

The mean age was 30.1 ± 5.3 years (n = 524). The mean body mass index (BMI) was 25.4 ± 5.6 kg/m(2), and 16.6% were obese (BMI ≥ 30.0 kg/m(2)). Under-reported EI was observed in 122 women (23.3%) with no over-reporters in the sample. Under-reporters were younger (P < 0.001), less likely to have a normal BMI (P = 0.002) and more likely to be obese (P < 0.001) than plausible reporters. Under-reporters had higher percentage of body-fat and lower percentage of body fat-free mass (P < 0.001), were more likely to be at risk of relative deprivation (P = 0.001) and reported a higher percentage of EI from carbohydrate (P = 0.02) than plausible reporters.

CONCLUSIONS

Observed differences between under-reporters and plausible reporters suggest that the exclusion of these under-reporters represents an important potential source of bias in obesity research among women in the periconceptional period.