Examining and Comparing the Validity and Reproducibility of Scales to Determine the Variety of Vegetables Consumed: Validation Study

BACKGROUND

Previous studies have reported that vegetable variety reduces the risk for noncommunicable diseases independent of the amount consumed.

OBJECTIVE

This study aimed to examine and compare the validity and reproducibility of several scales to determine vegetable variety.

METHODS

In total, 23 nutrition students in Japan reported their vegetable intake over the past month using a self-administered questionnaire between July and August 2021. Specifically, four scales were used: (1) a single question regarding the number of vegetables consumed (scale A); (2) a scale containing 9 vegetable subgroups included in the brief-type self-administered diet history questionnaire (scale B); (3) a scale containing 19 vegetable items included in a self-administered diet history questionnaire (scale C); and (4) a scale containing 20 vegetable items from the Ranking of Vegetable Consumers in Japan, which was analyzed based on a report on the National Health and Nutrition Survey in Japan (scale D). Scale validity was assessed by correlation with the number of vegetables consumed, which was collected from dietary records for 7 consecutive days. Reproducibility was assessed by test-retest reliability.

RESULTS

Regarding the validity of the 4 scales, significant correlations were found between scales C (ρ=0.51) and D (ρ=0.44) with vegetable variety based on dietary records, but scales A (ρ=0.28) and B (ρ=0.22) were not significantly correlated. Reproducibility showed a significant correlation in scale B (ρ=0.45) and strong correlations in scales C (ρ=0.73) and D (ρ=0.75).

CONCLUSIONS

The scales for vegetable items have acceptable validity and reproducibility compared to the scales that used a single question or vegetable subgroup and, therefore, may determine the variety of vegetables consumed.

Time Trends in Income-related Differences in Food Group Intakes: The National Health and Nutrition Survey, Japan in 2010, 2014, and 2018

BACKGROUND

We aimed to clarify whether differences in food group intake according to household income have changed over the last decade in Japanese people aged 20 years or older.

METHODS

This cross-sectional study was based on the 2010, 2014, and 2018 National Health and Nutrition Surveys in Japan. Food intake was assessed using a 1-day semi-weighed household dietary record. The participants were categorized into three groups based on their income. The mean of each food intake according to the income group was estimated by adjusting for age, occupation, and number of participants from the same household. The significance of the interaction terms between income and survey year was evaluated to assess the change in income-related differences in food intake over time.

RESULTS

Cereal intake was lower in the middle- and the highest-income groups than in the lowest-income group, regardless of sex, and the interaction between income and year was nonsignificant for cereal intake. In the former two surveys, vegetable intake was higher among the highest-income women, while in the 2018 survey, the vegetable intake decreased in the women in the middle- and the highest-income groups. The interaction between income and year was significant for vegetable intake among the women. For other foods, the differences in intake among the income groups did not significantly change over time.

CONCLUSION

The tendency for lower cereal intake in the higher-income groups was consistent over time in both the sexes, and the tendency for higher vegetable intake in the highest income women disappeared over time.

National Nutrition Surveys Applying Dietary Records or 24-h Dietary Recalls with Questionnaires: A Scoping Review

Development of an accurate and efficient dietary method is required for national nutrition surveys. Some countries conduct dietary surveys and combine 24-h dietary records or 24-h dietary recalls with dietary questionnaires. This scoping review aimed to summarize studies that used results from national surveys that combined detailed dietary surveys (dietary records or 24-h dietary recall) and dietary questionnaires and identify the purpose of combining the two methods. The PubMed database and manual searches were used for the literature review. We extracted 58 articles from 16 national nutrition surveys from 14 countries. Most studies used 24-h dietary recall for detailed dietary surveys and the food frequency questionnaire (FFQ) or food propensity questionnaire (FPQ) for questionnaire surveys. Among 37 studies from eight countries, the purpose of combining the two dietary survey methods was to estimate energy and nutrient intakes from detailed dietary surveys and habitual food intake from questionnaires. These findings are useful as a reference when introducing new dietary survey methods in future national nutrition surveys.

Is Energy Expenditure or Physical Activity Considered When Energy Intake Is Measured? A Scoping Review 1975-2015

The health-transitions humans have delivered during the 20th Century associated with the nutrition is that from undernutrition to obesity, which perseveres in the current years of the 21st Century. Energy intake (EI) is a contributing factor and therefore a fascination in nutritional sciences. However, energy expenditure (EE) has not been usually considered as a conjoint factor. Thus, this study aimed to review if studies on adults consider data on dietary intake, specifically EI, and included data on EE and physical activity (PA). A search of MEDLINE from 1975 to December 2015 was managed. Our scoping review consisted of keywords related to EI, dietary allowances, and nutritional requirements. From 2229 acknowledged articles, 698 articles were finally taken fulfilling inclusion and quality criteria. A total of 2,081,824 adults (53.7% females) were involved, and most studies had been conducted in EEUU (241), Canada (42), Australia (30), Japan (32), and Brazil (14). In Europe, apart from UK (64), the Netherlands (31) and France (26) led the classification, followed by Sweden (18), Denmark (17), and France (26). Mediterranean countries are represented with 27 studies. A total of 76.4% did not include EE and 93.1% did not include PA. Only 23.6% of the studies contained both EI and EE. A large methodological diversity was perceived, with more than 14 different methods regarding EI, and more than 10 for EE. PA was only analyzed in scarce articles, and scarcely considered for interpretation of data and conclusions. Moreover, PA was often measured by subjective questionnaires. Dietary surveys show a large diversity regarding methodology, which makes comparability of studies difficult. EE and PA are missing in around 80% of studies or are not included in the interpretation of results. Conclusions regarding EI or diet adequacy in adults should not be taken without analyzing EE and PA.

A Systematic Review and Meta-Analysis of Validation Studies Performed on Dietary Record Apps

Mobile dietary record apps have been increasingly validated by studies with various study designs. This review aims to evaluate the overall accuracy of dietary record apps in measuring the intake of energy, macro- and micronutrients, and food groups in real-life settings and the designs of validation studies. We systematically searched mobile dietary record validation studies published during the period from 2013 to 2019. We identified 14 studies for the systematic review, of which 11 studies were suitable for meta-analyses on energy intake and 8 studies on macronutrient intake. Mean differences and SDs of nutrient estimations between the app and the reference method from studies were pooled using a random-effects model. All apps underestimated energy intake when compared with their reference methods, with a pooled effect of -202 kcal/d (95% CI: -319, -85 kcal/d); the heterogeneity of studies was 72%. After stratification, studies that used the same food-composition table for both the app and the reference method had a lower level of heterogeneity (0%) and a pooled effect of -57 kcal/d (95% CI: -116, 2 kcal/d). The heterogeneity of studies in the differences in carbohydrate, fat, and protein intake was 54%, 73%, and 80%, with the pooled effect of -18.8 g/d, -12.7 g/d, and -12.2 g/d, respectively, after excluding outliers. The intakes of micronutrients and food groups were statistically nonsignificantly underestimated by the apps in most cases. In conclusion, dietary record apps underestimated food consumption compared with traditional dietary assessment methods. Moreover, varying study designs have been found across studies. Recommended practices for conducting validation studies were formulated including considering biomarkers as the reference, testing in a larger and more representative study population for a longer period, avoiding the learning effect of each method, and comparing food group or food item consumption in addition to comparing energy and nutrient intakes.

Associations of mothers' source of feeding information with longitudinal trajectories of sugar-sweetened beverage intake, 100% juice intake and adiposity in early childhood

BACKGROUND

There remains a need to understand how information sources can promote young children's healthy beverage consumption and prevent obesity.

OBJECTIVES

To examine associations of mothers' primary feeding information source with children's sugar-sweetened beverage (SSB) intake, 100% juice intake and adiposity between ages 3 and 7 years.

METHODS

We analyzed data from a prospective cohort study (n = 371 children; 13 visits). Mothers reported their primary feeding information source at baseline and completed child 3-day dietary records each visit. Child adiposity indicators were calculated from repeated height/weight measurements and dual-energy X-ray absorptiometry. Longitudinal models examined beverage intakes and adiposity over time by source.

RESULTS

Primary feeding information sources included doctors (48.2%), mothers (17.5%), grandmothers (13.5%), other healthcare professionals (11.3%) and other family/friends (9.4%). Children's juice intake with age differed by source (P interaction = 0.03), with steepest and slightest intake decreases in the doctor (-19.7% each year; 95% CI: -23.7%, -15.5%) and grandmother (-5.0%; -14.5%, 5.5%) subgroups, respectively. Children's SSB intake did not differ by source, but increased annually by 7.1% (4.5%, 9.8%) overall. The grandmother subgroup had the greatest child adiposity over time.

CONCLUSIONS

Mothers' primary feeding information source may have important, yet heterogeneous, influences on young children's beverage intakes and adiposity over time. Consistent evidence-based messages are likely needed.

Providing Comprehensive Dietary Fatty Acid Profiling from Saturates to Polyunsaturates with the Malaysia Lipid Study-Food Frequency Questionnaire: Validation Using the Triads Approach

To address limited food frequency questionnaire (FFQ) capacity in public health monitoring in Malaysia, we aimed to develop a semi-quantitative FFQ for an adult multiethnic population for comprehensive fatty acid (FA) profiling inclusive of saturated (SFA), monounsaturated (MUFA), polyunsaturated fatty acids (PUFA), PUFA:SFA ratio, trans fatty acids, omega-3 and omega-6 FAs. A 240-food itemed FFQ used diet records (DR) of Malaysia Lipid Study (MLS) participants and fatty acid composition database from laboratory analyzed foods. The developed MLS-FFQ underwent face and content validation before relative validation in a free-living population (n = 114). Validation was facilitated for macronutrient data comparisons between DR and FFQ via Spearman’s correlation coefficient analyses; and for fatty acid composition data by independent pairing of DR, FFQ and plasma triglyceride using the triads method. Moderate correlation between dietary methods was obtained for macronutrients and FAs (r = 0.225–0.457, p < 0.05) except for ω-3 FAs, presenting good agreement with grossly misclassified nutrients <10%. For fatty acid composition data, the magnitude of validity coefficients (z) for SFA, PUFA, PUFA:SFA ratios and ω-6 FAs by all 3 methods were not significantly different (p > 0.05). In conclusion, the MLS-FFQ was shown to be a valid tool to assess population dietary intakes.

The Major Source of Antioxidants Intake From Typical Diet Among Rural Farmers in North-eastern Japan in the 1990s

Background

Previous Japanese studies have led to the erroneous conclusion of antioxidant capacity (AOC) intakes of the overall Japanese diet due to limitations in the number and types of food measured, especially in rice and seafood intake. The aims of the study were to construct an AOC database of foods representative of the typical Japanese diet and to clarify the high contributors to AOC intake from the overall diet of the Japanese population.

Methods

Commonly consumed foods were estimated using 3-day dietary records (DRs) over the four seasons among 55 men and 58 women in Japan. To generate an AOC database suitable for the typical Japanese diet, hydrophilic (H-)/lipophilic (L-) oxygen radical absorbance capacity (ORAC) values of foods in each food group were measured via validated methods using the food intake rankings. Subsequently, we estimated the AOC intake and the AOC characteristics of a typical Japanese diet.

Results

Of 989 food items consumed by the participants, 189 food items were measured, which covered 78.8% of the total food intake. The most commonly consumed types of antioxidant-containing food were tea, soybean products, coffee, and rice according to H-ORAC, and soybean products, fish and shellfish, vegetables, and algae according to L-ORAC.

Conclusions

The characteristics of high AOC intake in rice and seafood more appropriately reflected the Japanese-style diet. Further studies are expected to clarify the association between food-derived AOC and its role in preventing or ameliorating lifestyle-related diseases.

Association of Protein Intake in Three Meals with Muscle Mass in Healthy Young Subjects: A Cross-Sectional Study

Protein intake of >0.24 g/kg of body weight (BW) at a single meal is necessary to maximize muscle protein synthesis in a young population. However, the association between the protein intake rate for three meals and muscle mass in the young population has not been evaluated. We hypothesized that a protein intake of >0.24 g/kg BW at all three meals is effective for maintaining muscle mass. Therefore, we cross-sectionally examined the association between protein intake at all three meals with muscle mass in 266 healthy young subjects (aged 21.4 ± 2.4 years). Subjects were divided into the AP group, which achieved protein intake >0.24 g/kg BW at all three meals; and the NP group, which did not. We calculated total fat-free mass (FFM) and appendicular fat-free mass (AppFFM) with dual-energy X-ray absorptiometry, and the percentage of total FFM (TotalFFM%) and appendicular FFM (AppFFM%) were calculated as the percentage of BW (%BW). We demonstrated that TotalFFM% (77.0 ± 0.5 vs. 75.2 ± 0.4%, p = 0.008) and AppFFM% (34.7 ± 0.3 vs. 34.1 ± 0.2%, p = 0.058) were higher in the AP than in the NP group. This finding suggests that achieving protein intake of >0.24 g/kg BW at all three meals is important for muscle mass maintenance in young populations.

The relative validity of a food record using the smartphone application MyFitnessPal

AIM

The present study aimed to validate food records on the application MyFitnessPal (MFP), comparing them with paper-based food records (P-FR).

METHODS

Thirty university students, including males and females, volunteered and recorded dietary intakes on P-FR and MFP food records (MFP-FR). The values of energy, macronutrients and fibre from MFP-FR were compared with data from P-FR, calculated using Brazilian food composition tables. Adjustments for in-person variability and energy intake were performed, and comparisons were made between each data set, using the Wilcoxon signed-rank test, Spearman's correlation and Bland-Altman agreement plots.

RESULTS

Positive moderate correlations between P-FR and MFP-FR for all variables, and non-significant associations for energy and fibre were found. The Bland-Altman plots showed tendency to underestimation and relatively narrow limits of agreement. Carbohydrate and lipids show trends of increasing the degree of overestimation with increased intake, even after data normalisation.

CONCLUSIONS

MFP tends to underestimate ingestion of nutrients probably due to inadequacies in the MFP database. However, MFP showed good relative validity, especially for energy and fibre. Its use, as well as other similar applications, should be encouraged, due to ease of assessing dietary information, although careful usage is recommended because of database gaps.

Using Personal Mobile Phones to Assess Dietary Intake in Free-Living Adolescents: Comparison of Face-to-Face Versus Telephone Training

Background

Traditional paper-based methods to assess food intake can be cumbersome for adolescents; use of mobile phones to track and photograph what they eat may be a more convenient, reliable, and compelling way to collect data.

Objective

Our aims were to determine (1) the feasibility of using personal mobile phones to send food records with digital images (FRDIs) among free-living adolescents and (2) whether the quality of food records differed between a high-level intervention group (ie, face-to-face training plus real-time support) and a low-level intervention group (ie, telephone training plus next-day follow-up).

Methods

Adolescents (N=42, 11 males and 31 females) aged 12-18 years who had a mobile phone with camera enrolled in the study via consecutive sampling. The first group (n=21) received face-to-face training while the second group (n=21) was trained via telephone. Participants received a fiducial marker (FM) and completed a 1-day FRDI using their mobile phones. At every eating occasion, participants were to (1) take clear images of their meals/food with a correctly placed fiducial marker before eating, (2) send the image immediately to a designated email address, (3) right after completing a meal, send a text message listing the time and name of the meal, foods eaten, and amounts eaten, and (4) before sleep, send an “end” text message to indicate completion of food recording. Those who received face-to-face training received real-time support during reporting; those trained by telephone received next-day follow-up. Descriptive statistics and comparison tests were used to determine performance of the groups.

Results

All participants (N=42) who underwent training completed their 1-day FRDI. A significantly greater proportion of the low-level intervention group compared to the high-level intervention group placed their FM correctly in the image (95% vs 43%, P<.001), had complete information for each meal in their food record (95% vs 71%, P=.04), and had a higher overall score in meeting the criteria for food recording (4.3 vs 3.4 out of 5 points). Both groups had energy intake values that moderately correlated with their estimated energy requirements: low-intervention r=.55; high-intervention r=.51.

Conclusions

Using personal mobile phones to report dietary intake via texting and digital images is feasible among free-living adolescents. Real-time support or high-level intervention does not guarantee better food recording quality among adolescents.

Major dietary patterns and risk of acute myocardial infarction in young, urban Pakistani population

Objective:

To investigate the role of dietary intake in the development of premature acute myocardial infarction (AMI) in a hospital-based Pakistani population in Karachi.

Methods:

In a case control study, 203 consecutive patients (146 males and 57 females) with their first AMI and age below 45 years were enrolled with informed consent. Similarly, 205 gender and age matched (within 3 years) healthy adults were also included as controls. Dietary intake of both cases and controls was assessed by using a simple 14-item food frequency questionnaire. Using factor analysis, 3 major dietary patterns- prudent dietary pattern, combination dietary pattern and western dietary pattern were identified. Fasting plasma/serum of both cases and controls were analyzed for homocysteine, folate, vitamin B₁₂, blood Pb, ferritin, cholesterol, LDL-cholesterol, HDL-cholesterol and triglycerides. ANOVA and conditional logistic regression were used to predict the association of dietary patterns with AMI.

Results:

Consumption of prudent diet, characterized by high consumption of legumes, vegetables, wheat, chicken and fruits, is protective against the risk of premature AMI. Moderate to high consumption of combination diet, characterized by high intake of eggs, fish, fruits, juices and coffee was associated with decreased risk of AMI. No association was observed between western diet, characterized by high intake of meat, fish and tea with milk and risk of AMI.

Conclusions:

Consumption of a prudent dietary pattern and a combination dietary pattern is protective against the risk of AMI in a Pakistani population.

Evaluation of a Web-Based Food Record for Children Using Direct Unobtrusive Lunch Observations: A Validation Study

Background

High-quality, Web-based dietary assessment tools for children are needed to reduce cost and improve user-friendliness when studying children’s dietary practices.

Objective

To evaluate the first Web-based dietary assessment tool for children in Norway, the Web-based Food Record (WebFR), by comparing children’s true school lunch intake with recordings in the WebFR, using direct unobtrusive observation as the reference method.

Methods

A total of 117 children, 8-9 years, from Bærum, Norway, were recruited from September to December 2013. Children completed 4 days of recordings in the WebFR, with parental assistance, and were observed during school lunch in the same period by 3 observers. Interobserver reliability assessments were satisfactory. Match, omission, and intrusion rates were calculated to assess the quality of the recordings in the WebFR for different food categories, and for all foods combined. Logistic regression analyses were used to investigate whether body mass index (BMI), parental educational level, parental ethnicity or family structure were associated with having a “low match rate” (≤70%).

Results

Bread and milk were recorded with less bias than spreads, fruits, and vegetables. Mean (SD) for match, omission, and intrusion rates for all foods combined were 73% (27%), 27% (27%), and 19% (26%), respectively. Match rates were statistically significantly associated with parental educational level (low education 52% [32%] versus high 77% [24%], P=.008) and parental ethnicity (non-Norwegian 57% [28%] versus others 75% [26%], P=.04). Only parental ethnicity remained statistically significant in the logistic regression model, showing an adjusted odds ratio of 6.9 and a 95% confidence interval between 1.3 and 36.4.

Conclusions

Compared with other similar studies, our results indicate that the WebFR is in line with, or better than most of other similar tools, yet enhancements could further improve the WebFR.

Comparison of a Web-Based Dietary Assessment Tool with Software for the Evaluation of Dietary Records

Background

Dietary assessment in clinical practice is performed by means of computer support, either in the form of a web-based tool or software. The aim of the paper is to present the results of the comparison of a Slovenian web-based tool with German software for the evaluation of four-day weighted paper-and-pencil-based dietary records (paper-DRs) in pregnant women.

Methods

A volunteer group of pregnant women (n=63) completed paper-DRs. These records were entered by an experienced research dietitian into a web-based application (Open Platform for Clinical Nutrition, OPEN, http://opkp.si/en, Ljubljana, Slovenia) and software application (Prodi 5.7 Expert plus, Nutri-Science, Stuttgart, Germany, 2011). The results for calculated energy intake, as well as 45 macro- and micronutrient intakes, were statistically compared by using the non-parametric Spearman’s rank correlation coefficient. The cut-off for Spearman’s rho was set at >0.600.

Results

12 nutritional parameters (energy, carbohydrates, fat, protein, water, potassium, calcium, phosphorus, dietary fiber, vitamin C, folic acid, and stearic acid) were in high correlation (>0.800), 18 in moderate (0.600–0.799), 11 in weak correlation (0.400–0.599), while 5 (arachidonic acid, niacin, alpha-linolenic acid, fluoride, total sugars) did not show any statistical correlation.

Conclusion

Comparison of the results of the evaluation of dietary records using a web-based dietary assessment tool with those using software shows that there is a high correlation for energy and macronutrient content.

Serum and adipose tissue fatty acid composition as biomarkers of habitual dietary fat intake in elderly men with chronic kidney disease

BACKGROUND

Fatty acid (FA) composition in serum cholesterol esters (CE) and adipose tissue (AT) reflect the long-term FA intake in the general population. Because both dietary intake and FA biomarkers associate with renal function, our aim was to identify which CE and AT FAs are useful biomarkers of habitual FA intake in individuals with chronic kidney disease (CKD).

METHODS

Cross-sectional analysis was performed in 506 men (aged 70 years) with a glomerular filtration rate (GFR) of <60 mL/min per 1.73 m(2) from the Uppsala Longitudinal Study of Adult Men cohort. Dietary habits were evaluated with a 7-day dietary record. FA compositions in CE and AT were analyzed by gas-liquid chromatography in two random subsamples of 248 and 318 individuals, respectively.

RESULTS

Both CE and AT linoleic acid and docosahexaenoic acid (DHA) were strongly associated with their corresponding intake, after adjustments for non-dietary factors. The proportions of eicosapentaenoic acid (EPA) and palmitic acid in CE and AT moderately correlated with dietary intake, whereas correlations of other FAs were weaker or absent. Proportions of EPA and DHA in CE and AT were positively associated with the total energy-adjusted fish intake. Results were confirmed in adequate reporters as identified by the Goldberg cutoff method. These relationships held constant, regardless of a GFR above or below 45 mL/min per 1.73 m(2) or the prevalence of microalbuminuria.

CONCLUSIONS

Proportions of EPA, DHA, palmitic and linoleic acid in serum CE and AT are good indicators of their dietary intake in men with CKD. They can be considered valid biomarkers for epidemiological studies and assessment of compliance.

Estimated portion sizes in a school-aged population

OBJECTIVE

To produce study-specific portion sizes for 11-year-old children in a population-based birth cohort and to compare these study-specific portion sizes with previously published children's portion sizes, to assess their relevance today.

DESIGN

Two multiple-pass 24 h dietary recalls were taken. The Food Standard Agency's photographic food atlas was used to quantify intakes. Study-specific food portion sizes were calculated for each food group. Portion sizes were calculated for all children and separately for boys and girls. The nutrient intake from the 24 h dietary recalls was analysed using study-specific and published portion sizes for individual participants. Agreement was assessed using Pearson's correlation, intra-class correlation coefficients and the Bland-Altman method.

SETTING

Birth cohort study, UK.

SUBJECTS

Children (mean age 11.3 years, n 264) and parents/guardians.

RESULTS

A total of 124 food portion sizes were calculated. Differences in portion weights between boys and girls were seen only for seven food items. There was a significant positive relationship (P < 0.001) between intakes of each nutrient as determined by the two sets of portion sizes. Correlation coefficients ranged from 0.77 (protein) to 0.98 (β-carotene). The intra-class correlation coefficients showed good agreement between nutrient intakes determined by the study-specific and published portion sizes (P < 0.001).

CONCLUSIONS

Nutrient intakes calculated using portion sizes from our population were similar to those calculated from portion size data collected in a national survey, despite being collected over a decade later. The present study adds to the small amount of evidence regarding portion sizes in UK children and shows agreement with previously published paediatric portion sizes.

Nutritional Intake of Young Italian High-Level Soccer Players: Under-Reporting is the Essential Outcome

It is recognized that much of the dietary data on adolescents and athletes is prone to reporting error, mostly through under-reporting. Nevertheless, in the majority of studies assessing the nutritional intake of young soccer players under-reporting has not been taken into consideration. The purpose of this study was to assess the dietary intake of a sample of young male Italian high-level soccer players on two time points to evaluate the degree of under- reporting. Seventy-five male high level soccer players (age range: 15-17 years) completed 4-day food records on two separate occasions (T0; T1, 3 months after T0). Under-reporting was assessed by the ratio of reported estimated energy intake (EEI) to estimated energy expenditure (EEE). Forty- three subjects, whose food records were judged accurate enough both at T0 and T1, were included in the data analysis (inclusion rate 57.3%). No significant weight changes were documented between T0 and T1 and in the two weeks preceding both T0 and T1. Reported mean daily energy intake was significantly lower than mean estimated daily energy expenditure both at T0 and T1 (p < 0.001). The average EEI/EEE ratio was 0.75 + 0.2 both at T0 and T1. It was ≤ 80% in 27 subjects (62.8%) at T0 and in 23 (53.4%) at T1; it reached 50% in 4 subjects both at T0 and T1. The degree of under- reporting of the young soccer players was in line with the available data on this age group. This study emphasizes that under-reporting is a critical issue in the evaluation of young athletes dietary intake, which should be considered in the interpretation of data, particularly when energy inadequacies are reported. Further studies with uniformed methods are needed, in order to reduce the degree of under-reporting, obtain reliable data on the dietary intake of young soccer players and evaluate the efficacy of targeted nutrition education programs. Key pointsUnder-reporting is a critical issue in the evaluation of young athletes' dietary intake, which should be always considered in the interpretation of data.The young athletes' motivation and parents' co-operation are key points that should be enhanced in this kind of studies.The nutritional intakes of young Italian high-level soccer players are likely to be qualitative inadequate, due to excessive cholesterol and very poor fiber intakes.

Validity of a self-administered food frequency questionnaire used in the 5-year follow-up survey of the JPHC Study to assess selenium intake: comparison with dietary records and blood levels

Selenium (Se) levels in serum and erythrocytes were measured in 215 adults to assess the relative validity of Se intake estimated from 28-day dietary records (DR) and the food frequency questionnaire (FFQ) used in the 5-year follow-up survey of the JPHC study. Se intake estimated from DR was correlated with that from the FFQ both in males and females (r=0.36 and r=0.32, respectively). Se levels in erythrocytes were weakly correlated with Se intake by DR for men (r=0.21) after adjustments for the total energy intake, though no significant correlation was found for women nor in crude values for either sex. Although Se intake estimated from our FFQ was correlated with that from the DR, no correlation was observed between the Se level in serum and estimated Se intake. In this population, the serum Se level was not a good biomarker for estimated Se intake.