Dutch food bank recipients have poorer dietary intakes than the general and low-socioeconomic status Dutch adult population.

PURPOSE: Food-assistance program users are a specific group of nutritional concern, as they are often food insufficient and have poorer diet quality compared to non-food-assistance program users. The aim of our study was to assess dietary intake of Dutch food bank recipients (n = 167) and to compare this with dietary intake of a representative sample of the general population (Dutch National Food Consumption Survey (DNFCS-all): n = 1933), including a low-socioeconomic status (SES) sample (DNFCS-low SES: n = 312), using data from the DNFCS 2007-2010. METHODS: In this cross-sectional study, 12 food banks throughout The Netherlands participated. Food bank recipients' characteristics were assessed with a self-administered questionnaire. Dietary intake data were collected through three 24-h recalls. Habitual dietary intake (mean, percentiles, and 95% CI) was estimated for all samples. Differences between samples were determined by comparing the 95% CIs. RESULTS: Mean age of the study population (62.9% female) was 48.6 years (SD:10.1). Mean energy intake was 1986 (95% CI 1830-2089) kcal. The majority of the Dutch food bank recipients had lower intakes than dietary reference intakes for dietary fiber, fruit, vegetables, and fish (range 86.6-99.3%), and a higher intake for saturated fat [88.1% (95% CI 84.1-98.9)]. Furthermore, mean intakes of energy, fiber, fruit, and vegetables were significantly lower in Dutch food bank recipients than in the DNFCS-all and the DNFCS-low-SES [e.g., daily mean fruit intake (g) food bank recipients 62.8 (95% CI 45.5-76.5), DNFCS-all 105.8 (95% CI 105.4-117.9), and DNFCS-low-SES 85.1 (95% CI 78.7-100.2)]. Fish intake was significantly lower compared with the DNFCS-all, but not compared with the DNFCS-low-SES. CONCLUSIONS: Dutch food bank recipients, who largely rely on the content of food parcels, are not able to meet the nutritional guidelines for a healthy diet, and their dietary intake is poorer than the general as well as the low-SES sample of the Dutch adult population. More research is needed on how to improve the dietary intake of this vulnerable population subgroup, by, e.g., revising the content of the food parcels, and to develop effective intervention activities.

Meal patterns across ten European countries - results from the European Prospective Investigation into Cancer and Nutrition (EPIC) calibration study.

OBJECTIVE: To characterize meal patterns across ten European countries participating in the European Prospective Investigation into Cancer and Nutrition (EPIC) calibration study. DESIGN: Cross-sectional study utilizing dietary data collected through a standardized 24 h diet recall during 1995-2000. Eleven predefined intake occasions across a 24 h period were assessed during the interview. In the present descriptive report, meal patterns were analysed in terms of daily number of intake occasions, the proportion reporting each intake occasion and the energy contributions from each intake occasion. SETTING: Twenty-seven centres across ten European countries. SUBJECTS: Women (64 %) and men (36 %) aged 35-74 years (n 36 020). RESULTS: Pronounced differences in meal patterns emerged both across centres within the same country and across different countries, with a trend for fewer intake occasions per day in Mediterranean countries compared with central and northern Europe. Differences were also found for daily energy intake provided by lunch, with 38-43 % for women and 41-45 % for men within Mediterranean countries compared with 16-27 % for women and 20-26 % for men in central and northern European countries. Likewise, a south-north gradient was found for daily energy intake from snacks, with 13-20 % (women) and 10-17 % (men) in Mediterranean countries compared with 24-34 % (women) and 23-35 % (men) in central/northern Europe. CONCLUSIONS: We found distinct differences in meal patterns with marked diversity for intake frequency and lunch and snack consumption between Mediterranean and central/northern European countries. Monitoring of meal patterns across various cultures and populations could provide critical context to the research efforts to characterize relationships between dietary intake and health.

Variety in vegetable and fruit consumption and the risk of gastric and esophageal cancer in the European Prospective Investigation into Cancer and Nutrition.

Diets high in vegetables and fruits have been suggested to be inversely associated with risk of gastric cancer. However, the evidence of the effect of variety of consumption is limited. We therefore investigated whether consumption of a variety of vegetables and fruit is associated with gastric and esophageal cancer in the European Prospective Investigation into Cancer and Nutrition study. Data on food consumption and follow-up on cancer incidence were available for 452,269 participants from 10 European countries. After a mean follow-up of 8.4 years, 475 cases of gastric and esophageal adenocarcinomas (180 noncardia, 185 cardia, gastric esophageal junction and esophagus, 110 not specified) and 98 esophageal squamous cell carcinomas were observed. Diet Diversity Scores were used to quantify the variety in vegetable and fruit consumption. We used multivariable Cox proportional hazard models to calculate risk ratios. Independent from quantity of consumption, variety in the consumption of vegetables and fruit combined and of fruit consumption alone were statistically significantly inversely associated with the risk of esophageal squamous cell carcinoma (continuous hazard ratio per 2 products increment 0.88; 95% CI 0.79-0.97 and 0.76; 95% CI 0.62-0.94, respectively) with the latter particularly seen in ever smokers. Variety in vegetable and/or fruit consumption was not associated with risk of gastric and esophageal adenocarcinomas. Independent from quantity of consumption, more variety in vegetable and fruit consumption combined and in fruit consumption alone may decrease the risk of esophageal squamous cell carcinoma. However, residual confounding by lifestyle factors cannot be excluded.

The maternal Mediterranean dietary pattern is associated with a reduced risk of spina bifida in the offspring.

OBJECTIVE: The objective of this study was to test the hypothesis whether a maternal dietary pattern is associated with the risk of spina bifida (SB) in the offspring. DESIGN: Case-control study. SETTING: Eight clinic sites in the Netherlands, 1999-2001. SAMPLE: A total of 50 mothers of children with SB and 81 control mothers. METHODS: Maternal food intakes were obtained by food frequency questionnaires at the standardised study moment of 14 months after the birth of the index child. Principal component factor analysis (PCA) and reduced rank regression (RRR) were used to identify dietary patterns. MAIN OUTCOME MEASURES: Maternal biomarkers were used as response measures in the RRR analysis and composed of serum and red blood cell (RBC) folate, serum vitamin B12 and total plasma homocysteine. The strength of the use of the dietary pattern in association with SB risk was estimated by odds ratios and 95% CI with the highest quartiles of the dietary pattern as reference. RESULTS: A predominantly Mediterranean dietary pattern was identified by both PCA and RRR. Those dietary patterns were highly correlated (r = 0.51, P < 0.001) and characterised by joint intakes of fruit, vegetables, vegetable oil, alcohol, fish, legumes and cereals and low intakes of potatoes and sweets. We observed a significantly increased risk of SB offspring in mothers with a weak use of the Mediterranean dietary pattern, OR 2.7 (95% CI 1.2-6.1) and OR 3.5 (95% CI 1.5-7.9). The Mediterranean dietary pattern was correlated with higher levels of serum and RBC folate, serum vitamin B12 and lower plasma homocysteine. CONCLUSION: The Mediterranean dietary pattern seems to be associated with reduction in the risk of offspring being affected by SB.

Dietary polyunsaturated fat intake is associated with low-density lipoprotein size, but not with susceptibility to oxidation in subjects with impaired glucose metabolism and type II diabetes: the Hoorn study.

OBJECTIVE: A high monounsaturated fatty acid (MUFA) and polyunsaturated fatty acid (PUFA) intake is associated with lower plasma low-density lipoprotein (LDL)-cholesterol. However, PUFA may increase the susceptibility of LDL to undergo oxidative modifications. The aim of this study was to analyze the association of habitual dietary fat intake with LDL size and oxidizability. DESIGN: Cross-sectional. SETTING: Cohort study. SUBJECTS: Seven hundred and fifty-eight subjects with normal, impaired glucose metabolism and type II diabetes. INTERVENTIONS: Mean LDL size was measured by high-performance gel-filtration chromatography. In vitro oxidizability of LDL was determined by measuring lag time, reflecting the resistance of LDL to copper-induced oxidation. Information about dietary fat intake was obtained by a validated food frequency questionnaire. RESULTS: PUFA intake (energy percent) was significantly and negatively associated with LDL size in subjects with type II diabetes (standardized beta (95% confidence interval) -0.17 (-0.28;-0.06)) and impaired glucose metabolism - although not statistically significant - (-0.09 (-0.24;0.05)), but not in subjects with normal glucose metabolism (0.01 (-0.10;0.12)) (P-value for interaction=0.02). No significant associations were observed for total, saturated fat and MUFA intake with LDL size. Intake of fat was associated with lag time; however, the small magnitude of the associations suggested that the composition of dietary fat is not a major factor affecting lag time. The same association with lag time was observed in all three glucose metabolism categories. CONCLUSIONS: In individuals with abnormal glucose metabolism, higher PUFA intake is associated with smaller LDL particle size, but does not alter the susceptibility of LDL to in vitro oxidation. SPONSORSHIP: Dutch Diabetes Research Foundation, and the Nederlandse Organisatie voor Wetenschappelijk Onderzoek (NWO).

Reproducibility and relative validity of a food frequency questionnaire to estimate intake of dietary phylloquinone and menaquinones.

BACKGROUND/OBJECTIVES: This study aims to investigate the reproducibility and relative validity of the Dutch food frequency questionnaire (FFQ), to estimate intake of dietary phylloquinone and menaquinones compared with 24-h dietary recalls (24HDRs) and plasma markers of vitamin K status. SUBJECTS/METHODS: In a cross-sectional study among 63 men and 58 women, the FFQ was completed three times over a 1-year period and the reproducibility was calculated over these measurements. Twelve-monthly 24HDR were collected to estimate relative validity. In addition, the relative validity of the FFQ, compared with plasma phylloquinone and desphospho-uncarboxylated matrix Gla protein (dpucMGP), was assessed cross-sectionally among 507 postmenopausal women. RESULTS: Intraclass correlations showed a good reproducibility, with correlations ranging from 0.65 to 0.83. The relative validity for phylloquinone intake compared with 24HDR was lower for women (rs=0.28) than men (rs=0.40). The relative validity, compared with 24HDR, for intake of short-chain menaquinones were ranging between 0.30 and 0.34. Long-chain menaquinones showed good relative validity (rs=0.60-0.69). Plasma phylloquinone concentrations were weakly correlated with phylloquinone intake (rs=0.16 (0.07-0.24). Plasma dpucMGP was negatively but weakly correlated with phylloquinone intake (rs=-0.09 (-0.18; -0.01)) and long-chain menaquinones (rs=-0.13 (-0.21; -0.04)), but not with short-chain menaquinones (rs=-0.04 (-0.13; 0.05)). CONCLUSIONS: The FFQ is reproducible to rank subjects for phylloquinone and menaquinone intake.The relative validity of our FFQ, compared with 24HDR, to estimate intake of phylloquinone and short-chain menaquinones was low, but the relative validity for long-chain menaquinones was good. The relative validity of our FFQ, compared with plasma phylloquinone and dpucMGP, was relatively low for both phylloquinone and menaquinone intake.

[Folic acid fortification: prevention as well as promotion of cancer]. / Foliumzuurverrijking: zowel preventie als bevordering van kanker.

In many countries foods are fortified with folic acid to prevent neural-tube defects. Beneficial effects on cancer, cardiovascular diseases and dementia are also assumed. Fortification with folic acid is not allowed in The Netherlands, although exemption can be granted. As well as beneficial effects, harmful effects may also occur. In addition to masking vitamin-B12 deficiency, there is some evidence that folic acid may promote progression of established tumours in laboratory animals and humans. In addition, it has been hypothesized that fortification with folic acid may have further negative effects on cancer through genetic selection. Given the high prevalence of cancer, these potentially harmful effects should also be taken into account in the Dutch debate on the advantages and disadvantages of folic acid fortification.

Strengthening the Reporting of Observational Studies in Epidemiology - nutritional epidemiology (STROBE-nut): An extension of the STROBE statement.

Concerns have been raised about the quality of reporting in nutritional epidemiology. Research reporting guidelines such as the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement can improve quality of reporting in observational studies. Herein, we propose recommendations for reporting nutritional epidemiology and dietary assessment research by extending the STROBE statement into Strengthening the Reporting of Observational Studies in Epidemiology - Nutritional Epidemiology (STROBE-nut). Recommendations for the reporting of nutritional epidemiology and dietary assessment research were developed following a systematic and consultative process, co-ordinated by a multidisciplinary group of 21 experts. Consensus on reporting guidelines was reached through a three-round Delphi consultation process with 53 external experts. In total, 24 recommendations for nutritional epidemiology were added to the STROBE checklist. When used appropriately, reporting guidelines for nutritional epidemiology can contribute to improve reporting of observational studies with a focus on diet and health.

Plasma carotenoids as biomarkers of intake of fruits and vegetables: ecological-level correlations in the European Prospective Investigation into Cancer and Nutrition (EPIC).

OBJECTIVE: The aim of this study was to assess the ability of a single 24-h dietary recall (24HDR) and food questionnaires (FQ) to predict plasma carotenoid levels at the ecological level by assessing the relationship between mean plasma carotenoid levels and mean intake of fruit and vegetables measured by 24HDR and FQ across 16 European regions. DESIGN: A random subsample of 3089 subjects was included, stratified by age and gender. They provided blood samples and dietary information between 1992 and 2000 as part of the European Prospective Investigation into Cancer and Nutrition. RESULTS: Using Spearman's correlation coefficients, the correlations between mean regional 24HDR fruit and vegetable variables and corresponding mean plasma carotenoid levels were generally higher than the correlations using FQ means. The highest correlation was between the 24HDR citrus fruit variable and beta-cryptoxanthin (r = 0.90). For 24HDR, total fruits and vegetables were highly correlated with lutein, zeaxanthin, and beta-cryptoxanthin (r = 0.83-0.87), while vegetables were more closely related with lutein (r = 0.69) and zeaxanthin (r = 0.68), and fruits correlated with zeaxanthin (r = 0.87) and beta-cryptoxanthin (r = 0.84). Root vegetables (r = 0.81) and total carrots (r = 0.71) were well correlated with alpha-carotene. In the multivariate models adjusting for age, body mass index, and season, and using observations of means stratified by sex and region, the association was generally higher for 24HDR compared to FQ. CONCLUSION: Mean regional intakes of fruits and vegetables in several European countries were closely correlated with corresponding mean plasma levels of individual carotenoids. Fruits and vegetables measured by 24HDR were generally better able to predict plasma carotenoids at the ecological level.

Plasma carotenoids as biomarkers of intake of fruits and vegetables: individual-level correlations in the European Prospective Investigation into Cancer and Nutrition (EPIC).

OBJECTIVE: The aim in this study was to assess the association between individual plasma carotenoid levels (alpha-carotene, beta-carotene, lycopene, beta-cryptoxanthin, lutein, zeaxanthin) and fruit and vegetable intakes recorded by a calibrated food questionnaire (FQ) and 24-h dietary recall records (24HDR) in nine different European countries with diverse populations and widely varying intakes of plant foods. DESIGN: A stratified random subsample of 3089 men and women from nine countries participating in the European Prospective Investigation into Cancer and Nutrition (EPIC), who had provided blood samples and dietary and other lifestyle information between 1992 and 2000, were included. RESULTS: beta-Cryptoxanthin was most strongly correlated with total fruits (FQ r = 0.52, 24HDR r = 0.39), lycopene with tomato and tomato products (FQ r = 0.38, 24HDR r = 0.25), and alpha-carotene with intake of root vegetables (r = 0.39) and of total carrots (r = 0.38) for FQ only. Based on diet measured by FQ and adjusting for possible confounding by body mass index (BMI), age, gender, smoking status, alcohol intake, and energy intake, the strongest predictors of individual plasma carotenoid levels were fruits (R(partial)(2) = 17.2%) for beta-cryptoxanthin, total carrots ((partial)(2) = 13.4%) and root vegetables (R(partial)(2) = 13.3%) for alpha-carotene, and tomato products (R(partial)(2) = 13.8%) for lycopene. For 24HDR, the highest R(partial)(2) was for fruits in relation to beta-cryptoxanthin (7.9%). CONCLUSIONS: Intakes of specific fruits and vegetables as measured by food questionnaires are good predictors of certain individual plasma carotenoid levels in our multicentre European study. At individual subject levels, FQ measurements of fruits, root vegetables and carrots, and tomato products are, respectively, good predictors of beta-cryptoxanthin, alpha-carotene, and lycopene in plasma.

Biochemical markers as additional measurements in dietary validity studies: application of the method of triads with examples from the European Prospective Investigation into Cancer and Nutrition.

The validity coefficient of dietary questionnaire measurements can be estimated from a triangular comparison between questionnaire, reference, and biochemical marker measurements with the method of triads. The method assumes that the measurements are linearly related to true intake and have independent random errors. We applied the method of triads to examples from the European Prospective Investigation into Cancer and Nutrition. In some examples, Heywood cases occurred, ie, the estimated validity coefficients were > 1 or the validity coefficients were not estimable. Such results are caused by random sampling fluctuations or violation of the model assumptions. One possible violation is a positive correlation between the random errors of questionnaire and reference measurements. We used a bootstrap method to estimate CIs for the validity coefficients. Validity studies with several hundred subjects, more accurate biochemical indicators of dietary intake, or both, are needed to estimate validity coefficients precisely and avoid complications with the bootstrap method.

alpha-Linolenic acid intake is not beneficially associated with 10-y risk of coronary artery disease incidence: the Zutphen Elderly Study.

BACKGROUND: Data on the relation between alpha-linolenic acid intake and coronary artery disease (CAD) are limited. Other dietary components appear to modify the reported relation between alpha-linolenic acid intake and CAD. OBJECTIVE: We examined whether dietary alpha-linolenic acid intake was inversely associated with risk of CAD. DESIGN: We prospectively studied 667 men aged 64-84 y from the Zutphen Elderly Study who were free of CAD at baseline. Dietary intake was assessed by using a cross-check dietary history method. RESULTS: During the 10-y follow-up, we documented 98 cases of CAD. After adjustment for age, standard coronary risk factors, and intake of trans fatty acids and other nutrients, alpha-linolenic acid intake was not significantly associated with CAD risk. The relative risk of CAD for the highest compared with the lowest tertile of alpha-linolenic acid intake was 1.68 (95% CI: 0.86, 3.29). alpha-Linolenic acid intake from sources containing trans fatty acids was also nonsignificantly, yet positively, associated with CAD risk. alpha-Linolenic acid intake from foods that did not contain trans fatty acids was not associated with CAD risk, the relative risk of CAD for the highest compared with the lowest tertile was 1.15 (95% CI: 0.63, 2.11). CONCLUSION: We did not observe a beneficial effect of dietary alpha-linolenic acid intake on the risk of 10-y CAD incidence. Investigating this hypothesis was complicated by the association between intakes of alpha-linolenic acid and trans fatty acids. Given the results of current prospective studies, a protective cardiac effect of alpha-linolenic acid is questionable.

Plasma deoxycholic acid is related to deoxycholic acid in faecal water.

Bile acids are considered as a risk factor for colorectal carcinogenesis. They were analysed in samples of faecal water and plasma of fasting heparine blood from 23 urolithiasis patients. Linear regression showed that the highest percentage of variance (52%) was explained by the model: plasma deoxycholic acid (micromol/l) = -3.11 + 0.96(+/-0.25*) 10log deoxycholic acid in faecal water (micromol/l) + 0.35(+/-0.15*) pH of faecal water -0.41(+/-0.19#) defacation frequency (number of stools/day); *P < 0.05, #P = 0.055. In future studies, analysing blood levels of unconjugated deoxycholic acid may substitute faecal measurements.

Stability of blood (pro)vitamins during four years of storage at -20 degrees C: consequences for epidemiologic research.

We studied the effects of frozen storage on (pro)vitamin concentrations in EDTA-plasma and whole blood. Aliquots from 55 samples were analyzed before storage and after 3, 6, 12, 24, 36 and 48 months at -20 degrees C. Dramatic decreases occurred for EDTA-plasma concentrations of vitamin E between 6 and 12 months, vitamin A, total carotenoids and beta-carotene after 1 year, and whole blood niacin. A smaller decrease was observed for folic acid at 1 year of storage, but the level remained constant thereafter. The vitamins D, B6, B12 (EDTA-plasma), B1 and B2 (whole blood) showed no decline during 4 years of storage. With the exception of folic acid, the observed decreases varied considerably among subjects. Therefore using EDTA-plasma stored longer than 1 year at -20 degrees C will result in highly attenuated odds ratios when assessing the relationship between vitamin A, carotenoids, or vitamin E with a given disease. Attenuation will also occur when using niacin concentrations in whole blood stored for 4 years at -20 degrees C.

Do dietary and supplementary intakes of antioxidants differ with smoking status?

BACKGROUND: Differences in dietary and supplementary intake of antioxidants were determine between different categories of smokers and never-smokers. METHODS: Data from a large, cross-sectional, population-based study were used. Subjects (n = 4244) were divided into five smoking categories according to the number of cigarettes smoked per day. Differences in intake of antioxidants or frequency of supplement use were assessed using multiple linear regression analysis and multiple logistic regression analysis, adjusting for potential confounders such as age, body mass index, education level, alcohol intake, and total energy intake. RESULTS: Men who smoked > 20 cigarettes/day had significantly lower intakes of beta-carotene and especially ascorbic acid compared to those who never smoked, resulting from an almost 60% lower fruit intake. Moderate and heavy smoking women also had lower ascorbic acid and fruit intake but differences were not as large as in men. A higher percentage of female heavy smokers compared with never-smokers consumed vitamin C (21.1% versus 14.1%), vitamin E (5.6% versus 1.8%), and multivitamin supplements (18.5% versus 12.2%). Among men only the moderate smokers differed significantly from never-smokers in supplement intake, in the sense that male moderate smokers had a higher percentage of multivitamin use (15.3% versus 12.2%) compared to never-smokers. CONCLUSIONS: Male heavy smokers not only have a lower dietary antioxidant intake than never-smokers, but additionally seem to use supplementation relatively infrequently.

Validity and repeatability of a modified Baecke questionnaire on physical activity.

BACKGROUND: In a pilot study for the European Prospective Investigation into Cancer and Nutrition (EPIC) a modification of the Baecke questionnaire on physical activity was tested for repeatability and relative validity in a population of 134 men and women aged 20-70 years. METHODS: For the assessment of repeatability Pearson's correlation coefficients and percentages of agreement after classification in tertiles were computed between administrations of the questionnaire at baseline, and after 5 and 11 months. Relative validity was determined by comparing the questionnaire to a four times repeated 3-day activity diary. RESULTS: Repeatability after 5 and 11 months was good, with test-retest correlation coefficients between 0.65 and 0.89 for main sections of the questionnaire. The percentages of agreement, exceeding chance (Cohen's kappa) were 57% and 56% for men (at 5 and 11 months respectively) and 41% and 46% for women. The correlations with the diaries were 0.56 in men and 0.44 in women. Agreement apart from chance between classification in tertiles for both methods was 35% for men and 10% for women. CONCLUSIONS: These data show that repeatability is good and relative validity as compared to an activity diary is moderate but well within the range of values found in other studies. The questionnaire is more valid in men than in women.

Underreporting of energy, protein and potassium intake in relation to body mass index.

BACKGROUND: Differential underreporting of dietary intake by subgroups of body mass index (BMI) will confound associations between dietary intake and BMI-related diseases. We estimated the magnitude of BMI-related underreporting for energy, protein, and potassium intake for the Dutch cohorts of the European Prospective Investigation into Cancer and Nutrition (EPIC). METHODS: The study population consisted of 134 Dutch men and women, aged 21-71 years, who participated in a pilot of EPIC. Ratios of reported dietary intakes to biomarkers were used as measures for underreporting. Dietary intake was assessed by a food frequency questionnaire (FFQ) and repeated 24-hour dietary recalls. Biomarker for energy intake was calculated basal metabolic rate; for protein and potassium intake the biomarker was 24-hour urinary nitrogen and potassium excretion, respectively. The measures of underreporting were linearly regressed on BMI (in kg/m2). RESULTS: Significant negative regression coefficients were observed when regressing energy ratio on BMI with adjustment for physical activity (FFQ: beta = -0.04 for men, beta = -0.02 for women; 24-hour recalls: beta = -0.03 for men, beta = -0.04 for women). In men, a significant negative regression coefficient (beta = -0.03) was observed when regressing protein ratio on BMI; for the recalls however only after adjustment for age and education (beta = -0.02). In women, negative regression coefficients were also obtained, but for the FFQ only after exclusion of dieting women (both FFQ and 24-hour recalls: beta = -0.02). According to the recalls, but not the FFQ, a significant negative regression coefficient (beta = -0.02) was observed among women when regressing potassium ratio on BMI. CONCLUSIONS: In this Dutch population, BMI-dependent underreporting of 20-25% over the observed range of BMI is present for protein and energy, Further study on BMI-dependent underreporting of dietary intake in EPIC cohorts is warranted.

The Dutch EPIC food frequency questionnaire. I. Description of the questionnaire, and relative validity and reproducibility for food groups.

BACKGROUND: A self-administered food frequency questionnaire was developed for the Dutch cohort of the European Prospective Investigation into Cancer and Nutrition (EPIC). Habitual consumption of 178 food items can be calculated from the questionnaire data. METHODS: Reproducibility and relative validity for food group intake were investigated in a population of 121 Dutch men and Women. The questionnaire was administered three times at 6-month intervals in order to determine the reproducibility. To assess the relative validity 12 monthly 24-hour recalls served as the reference method. RESULTS: Spearman rank order correlation coefficients between estimates of food group intake assessed by repeated questionnaires ranged from 0.45 to 0.92. For men, Spearman correlation coefficients between estimates of food group intake based on the questionnaire and those based on 24-hour recalls ranged from 0.21 for cooked vegetables to 0.78 for sugar and sweet products, with a range of 0.61. For women the median was 0.53, with a minimum of 0.31 for vegetables and a maximum of 0.87 for alcoholic beverages. The photographs in the questionnaire for the estimation of portion sizes contributed little to the relative validity of the ranking of subjects. However, on the group level most median food group estimates based on photographic portion sizes were closer to the median intakes as assessed by 24-hour recalls than those based on standard portion sizes. CONCLUSIONS: The questionnaire seems adequate for ranking Dutch EPIC subjects according to intake of most food groups, although the relative validity for some food groups, such as vegetables and fish, remains of concern.

The Dutch EPIC food frequency questionnaire. II. Relative validity and reproducibility for nutrients.

BACKGROUND: A self-administered semi-quantitative food frequency questionnaire (FFQ) was developed for the Dutch cohort of the European Prospective Investigation into Cancer and Nutrition (EPIC). METHODS: The reproducibility and relative validity of nutrient intake as assessed by this questionnaire were investigated in a population of 121 men and women. To assess the relative validity, 12 monthly 24-hour recalls served as reference method, together with four determinations of 24-hour urinary nitrogen excretion, predicted basal metabolic rate, and serum beta-carotene and alpha-tocopherol levels. RESULTS: Protein and among women, energy intake were underestimated by the questionnaire compared to urinary nitrogen excretion and the basal metabolic rate, respectively. The underestimation for protein decreased with increasing protein intake. Pearson correlation coefficients between nutrient intakes assessed by repeated questionnaires ranged from 0.70 to 0.94 among men and from 0.59 to 0.94 among women. Correlation coefficients between nutrient intakes assessed by the questionnaire and 24-hour recalls ranged from 0.26 to 0.83 for men and from 0.35 to 0.90 for women, with medians of 0.59 and 0.58, respectively. Correlation coefficients between 0.2 and 0.5 were observed for beta-carotene and vitamin C for men and for beta-carotene and vitamin E for women. Associations with serum beta-carotene (r = -0.16 for men; 0.13 for women) and alpha-tocopherol (0.23 and 0.15, respectively) were much poorer than those obtained with 24-hour recalls. Correlations between protein intake and 24-hour urinary nitrogen excretion were 0.47 and 0.53, respectively. CONCLUSIONS: The FFQ seems adequate for ranking subjects according to intake of energy, macronutrients, dietary fibre and retinol, but it does not yield such good results for beta-carotene, vitamin C for men, vitamin E for women.

Estimation of reproducibility and relative validity of the questions included in the EPIC Physical Activity Questionnaire.

BACKGROUND: The EPIC core questionnaire on lifestyle contains a number of questions on physical activity designed to rank subjects according to level of physical activity (short PA questionnaire). These questions are based on a more extensive questionnaire designed to measure absolute total energy expenditure (extensive PA questionnaire), that was validated in a pilot study preceding EPIC. Reproducibility and relative validity of the short PA questionnaire were estimated by selecting, from the pilot study data, the answers to a number of questions from the extensive questionnaire that resembled those actually included in the short version. METHODS: The population of the pilot study consisted of 126 men and women aged between 20 and 70 years. Reproducibility was estimated by administering the extensive questionnaire three times: at baseline, and after 5 and 11 months. In order to determine the relative validity of the extensive questionnaire, a 3-day activity diary, repeated four times, was used as the reference method. RESULTS: Over the study period (13 months), mean absolute energy expenditure, estimated from the questions included in the short questionnaire, was fairly constant in men but not in women. REPRODUCIBILITY: Spearman correlation coefficients ranged from 0.47 to 0.89 in men, and from 0.49 to 0.81 in women. RELATIVE VALIDITY: Spearman correlation coefficients between the short questionnaire and the diary were between 0.32 and 0.81 for men, and between 0.28 and 0.72 for women. CONCLUSIONS: The questions selected for the short questionnaire are not suitable for estimating energy expenditure at an absolute level. Reproducibility and relative validity of the ranking of subjects seemed satisfactory and comparable to the extensive questionnaire. The results imply that the short questionnaire is suitable for ranking subjects in the EPIC study.