Optimization of a Food List for Food Frequency Questionnaires Using Mixed Integer Linear Programming: A Proof of Concept Based on Data from the Second German National Nutrition Survey.

Food Frequency Questionnaires (FFQs) are important instruments to assess dietary intake in large epidemiological studies. To determine dietary intake correctly, food lists need to be adapted depending on the study aim and the target population. The present work compiles food lists for an FFQ with Mixed Integer Linear Programming (MILP) to minimize the number of foods in the food list. The optimized food lists were compared with the validated eNutri FFQ. The constraints of the MILP aimed to identify food items with a high nutrient coverage in a population and with a high interindividual variability. The optimization was based on data from the second German National Nutrition Survey. The resulting food lists were shorter than the one used in the validated eNutri FFQ.

Unfavorable nutrient intakes in children up to school entry age: results from the nationwide German KiESEL study.

Background: Nutrition in the first years of life is a cornerstone for child development and long-term health, yet there is a lack of current data on energy and nutrient intake among toddlers and preschoolers in Germany. Objective: To analyze energy and nutrient intake in toddlers (1- to 2-year-olds) and preschoolers (3- to 5-year-olds) in Germany and compare the results with the Dietary Reference Values (DRVs) by the European Food Safety Authority. Design: Dietary intake was assessed by weighed food record data (3 + 1 day) of 890 children from the representative cross-sectional Children's Nutrition Survey to Record Food Consumption (KiESEL), carried out in 2014-2017 as a module of the German Health Interview and Examination Survey for Children and Adolescents Wave 2. For the calculation of energy and nutrient intake, the German Nutrient Database BLS 3.02, LEBTAB, and a supplement database were used. Results: Median intakes of energy and most nutrients met or exceeded the DRVs in both toddlers and preschoolers. However, low intakes relative to DRVs were found for vitamin D (6-9% of DRV, including supplements) and iodine (57-65% of DRV). Age specific downward deviations were observed for iron intake in toddlers (75% of DRV) and for calcium intake in preschoolers (67-77% of DRV). In contrast, intakes were high for saturated fatty acids (SFA) (14-16 E%), mono-/disaccharides (60-87 g/day), and protein [2.1-2.6 g/(kg body weight*day)]. Conclusion: Nutrient imbalances in toddlers and preschoolers in Germany, which are partly age-related, give rise to concern. Research is needed to determine if routine vitamin D supplementation should be extended beyond infancy. Public health efforts to increase the rate of use of iodized salt and to reduce the intake of SFA and mono-/disaccharides in children's diets are to be strengthened.

Attitudes, perceptions and behaviours regarding meat consumption in Germany: results of the NEMONIT study.

Meat consumption in Germany is presently higher than recommended for a healthy and sustainable nutrition. Therefore, the aim of the present study was to explore German consumers' attitudes, perceptions and behaviours regarding meat consumption based on data from 1807 participants (20-80 years) of the NEMONIT study (2012/13). Data were obtained using computer-assisted telephone interviews including 24-h recalls and a food-frequency questionnaire (FFQ). The majority (97 %) of the participants were meat consumers and most of them stated that an ideal meal should contain meat. Their main motives for meat consumption were good taste, usual habit and the perception of meat as a healthy and satiable food. The stated meat consumption frequency was higher than the 'desired' consumption frequency, answered in a FFQ. Most participants would agree with two meat meals per week, but only 17 % assumed that the German population would agree. Therefore, framework conditions do not motivate people enough to reduce their meat consumption. Options for action which can be implemented in daily routine are needed. Meat is still a largely appreciated food in Germany, but the results indicate a potential for behavioural changes which must be exploited urgently to reduce meat consumption to a healthy and sustainable level.

Association between body mass index and macronutrients differs along the body mass index range of German adults: results from the German National Nutrition Survey II.

The aim of the present study was to determine whether the association between body mass index (BMI) and the intake of macronutrients varies along the BMI distribution of German adults. Based on a sample of 9214 men and women aged 18-80 years from the representative cross-sectional German National Nutrition Survey (NVS) II, quantile regression was used to investigate the association between BMI and the intake of macronutrients independent of energy intake and other predictors. In both sexes, BMI was positively associated with the intake of total protein and animal protein over its entire range and negatively associated with vegetable protein. A negative association between BMI and the intake of polysaccharides was found along the entire range of BMI in men. There was a weak negative association between BMI and the intake of total fat and saturated fatty acids observed in normal-weight-range women only. In conclusion, the association between BMI and the intake of macronutrients varies along the BMI range. Animal protein intake is positively associated with BMI independent of energy intake in both sexes whereas only in men an inverse association of polysaccharide intake with BMI was shown.

Meat consumers and non-meat consumers in Germany: a characterisation based on results of the German National Nutrition Survey II.

Meat consumption in high-income countries is increasingly discussed due to its impact on environment and health as well as ethical considerations. The present paper aims to provide information on meat consumption behaviour, sociodemographic factors related to meat consumption and its associations with health and nutritional behaviour, based on the German National Nutrition Survey II. For 12 915 participants aged 18-80 years, food consumption was assessed by two 24-h recalls and further data by interviews. Participants were distinguished in non-meat consumers and meat consumers; meat consumers were further differentiated as low and high meat consumers (<86 g/d and ≥86 g/d). Group differences were analysed using binary logistic and linear regression models. More non-meat consumers were found among women, young and more educated persons. They showed equal or more preferable health characteristics, had a similar energy intake but ate more plant-based foods compared with meat consumers. More high meat consumers were found among men, young and middle-aged and lower-educated persons. Compared with low meat consumers, they showed equal or less preferable health characteristics, had a higher energy intake and ate more potatoes and sauces/spices and less of most other food groups in relation to their energy intake. To conclude, sociodemographic groups differ in their meat consumption and differences in meat consumption go together with differences in health behaviour and other food consumption.

Design and characterization of dietary assessment in the German National Cohort.

BACKGROUND/OBJECTIVES: The aim of the study was to describe a novel dietary assessment strategy based on two instruments complemented by information from an external population applied to estimate usual food intake in the large-scale multicenter German National Cohort (GNC). As proof of concept, we applied the assessment strategy to data from a pretest study (2012-2013) to assess the feasibility of the novel assessment strategy. SUBJECTS/METHODS: First, the consumption probability for each individual was modeled using three 24 h food lists (24h-FLs) and frequencies from one food frequency questionnaire (FFQ). Second, daily consumed food amounts were estimated from the representative German National Nutrition Survey II (NVS II) taking the characteristics of the participants into account. Usual food intake was estimated using the product of consumption probability and amounts. RESULTS: We estimated usual intake of 41 food groups in 318 men and 377 women. The participation proportion was 100, 84.4, and 68.5% for the first, second, and third 24h-FL, respectively. We observed no associations between the probability of participating and lifestyle factors. The estimated distributions of usual food intakes were plausible and total energy was estimated to be 2707 kcal/day for men and 2103 kcal/day for women. The estimated consumption frequencies did not differ substantially between men and women with only few exceptions. The differences in energy intake between men and women were mostly due to differences in estimated daily amounts. CONCLUSIONS: The combination of repeated 24h-FLs, a FFQ, and consumption-day amounts from a reference population represents a user-friendly dietary assessment approach having generated plausible, but not yet validated, food intake values in the pretest study.

Joint Data Analysis in Nutritional Epidemiology: Identification of Observational Studies and Minimal Requirements.

Background: Joint data analysis from multiple nutrition studies may improve the ability to answer complex questions regarding the role of nutritional status and diet in health and disease. Objective: The objective was to identify nutritional observational studies from partners participating in the European Nutritional Phenotype Assessment and Data Sharing Initiative (ENPADASI) Consortium, as well as minimal requirements for joint data analysis. Methods: A predefined template containing information on study design, exposure measurements (dietary intake, alcohol and tobacco consumption, physical activity, sedentary behavior, anthropometric measures, and sociodemographic and health status), main health-related outcomes, and laboratory measurements (traditional and omics biomarkers) was developed and circulated to those European research groups participating in the ENPADASI under the strategic research area of "diet-related chronic diseases." Information about raw data disposition and metadata sharing was requested. A set of minimal requirements was abstracted from the gathered information. Results: Studies (12 cohort, 12 cross-sectional, and 2 case-control) were identified. Two studies recruited children only and the rest recruited adults. All studies included dietary intake data. Twenty studies collected blood samples. Data on traditional biomarkers were available for 20 studies, of which 17 measured lipoproteins, glucose, and insulin and 13 measured inflammatory biomarkers. Metabolomics, proteomics, and genomics or transcriptomics data were available in 5, 3, and 12 studies, respectively. Although the study authors were willing to share metadata, most refused, were hesitant, or had legal or ethical issues related to sharing raw data. Forty-one descriptors of minimal requirements for the study data were identified to facilitate data integration. Conclusions: Combining study data sets will enable sufficiently powered, refined investigations to increase the knowledge and understanding of the relation between food, nutrition, and human health. Furthermore, the minimal requirements for study data may encourage more efficient secondary usage of existing data and provide sufficient information for researchers to draft future multicenter research proposals in nutrition.

Characterisation of vitamin and mineral supplement users differentiated according to their motives for using supplements: results of the German National Nutrition Monitoring (NEMONIT).

OBJECTIVE: To characterise German vitamin and mineral supplement users differentiated by their motives for supplement use. DESIGN: Data were obtained from the German National Nutrition Monitoring (2010/11) via two 24 h dietary recalls and a telephone interview. Motive-based subgroups of supplement users were identified by factor and cluster analysis. Sociodemographic, lifestyle, health and dietary characteristics and supplement use were examined. Differences were analysed using χ 2 tests, logistic and linear regression models. SETTING: Germany, nationwide. SUBJECTS: Individuals (n 1589) aged 18-80 years. RESULTS: Three motive-based subgroups were identified: a 'Prevention' subgroup (n 324), characterised by the motive to prevent nutrient deficiencies; a 'Prevention and additional benefits' subgroup (n 166), characterised by motives to prevent health problems and improve well-being and performance; and a 'Treatment' subgroup (n 136), characterised by motives to treat nutrient deficiencies or diseases. Members of the two prevention subgroups had a higher Healthy Eating Index score and tended to be more physically active than non-users. Those in the 'Prevention and additional benefits' subgroup supplemented with a greater number of micronutrients. Members of the 'Treatment' subgroup tended to be older and have a lower self-reported health status than non-users, and supplemented with a smaller number of micronutrients. CONCLUSIONS: The majority of supplement users take supplements for preventive purposes and they are more health conscious than non-users of supplements due to their concerns about developing health problems. Those supplementing for treatment purposes may have underlying health indications and may be more likely to benefit from supplementation than those supplementing for preventive purposes.

Inventory of surveillance systems assessing dietary, physical activity and sedentary behaviours in Europe: a DEDIPAC study.

Background: There is a need for harmonized public health surveillance systems to monitor regional variations and temporal trends of health behaviours and health outcomes and to align policies, action plans and recommendations in terms of healthy diet and physical (in)activity within Europe. We provide an inventory of currently existing surveillance systems assessing diet, physical activity, and sedentary behaviours in Europe as a tool to assist in the identification of gaps and needs and to contribute to the roadmap for an integrated pan-European surveillance system. Methods: An inventory questionnaire was completed by representatives of eleven European countries. Eligible surveillance systems were required to meet specific inclusion criteria. First, pre-screening of available surveillance systems in each country was conducted. Second, an in-depth appraisal of the retained surveillance systems complying with the pre-defined requirements was performed. Results: Fifty surveillance systems met the inclusion criteria: six multinational European surveys and forty-four national surveys. Dietary intake and physical activity are the domains predominantly assessed and adults are the most frequently studied age group. Conclusions: Many on-going activities were identified at the national level focussing on adults, but fewer surveillance systems involving vulnerable groups such as infants and pre-school children. Assessment of sedentary and dietary behaviours should be more frequently considered. There is a need for harmonization of surveillance methodologies, indicators and target populations for between-country and over time comparisons. This inventory will serve to feed future discussions within the DEDIPAC-JPI major framework on how to optimize design and identify priorities within surveillance.

Energy and macronutrient intake over the course of the day of German adults: A DEDIPAC-study.

The aim of the study was to analyze the energy and macronutrient intake over the course of the day of selected population groups in Germany defined by sex, age, BMI, SES, and diet quality. The study was based on food consumption data from the German National Nutrition Survey II (2005-2007) assessed by two 4-day dietary weighing records of 662 women and men aged between 18 and 80 years. Energy and macronutrient intake were calculated using the German Nutrient Database 3.02 and summarized for the periods 'morning', 'midday', 'afternoon', 'evening', and 'night'. Generalized estimating equation models were used to examine differences in energy and macronutrient intake. For women and men, a three-main-meal pattern ('morning', 'midday', and 'evening') was observed, indicated as peaks in energy intake at 08:00 to 09:00, 13:00 and 19:00 o'clock. The distributions of carbohydrate, protein, and fat intake mirror the distribution of energy intake over the course of the day. The highest energy intake was found in the 'evening' period, especially in young adults, overweight persons, persons with a high SES, and men with a low diet quality. Women of the oldest age group showed a similar energy intake across the three-main-meals in contrast to young adults, who had lower peaks in the 'morning' and 'midday' periods as well as a shift to later meal times. Young adults seem to have a higher variability in energy intake and a less distinct meal pattern, while seniors have a more structured day. Because a high energy intake in the 'evening' period is associated with negative health-related factors, the distribution of energy intake should be considered by recommendations for a healthy nutritional behavior.

Predictors of BMI Vary along the BMI Range of German Adults - Results of the German National Nutrition Survey II.

OBJECTIVE: The objective of the study was to identify predictors of BMI in German adults by considering the BMI distribution and to determine whether the association between BMI and its predictors varies along the BMI distribution. METHODS: The sample included 9,214 adults aged 18-80 years from the German National Nutrition Survey II (NVS II). Quantile regression analyses were conducted to examine the association between BMI and the following predictors: age, sports activities, socio-economic status (SES), healthy eating index-NVS II (HEI-NVS II), dietary knowledge, sleeping duration and energy intake as well as status of smoking, partner relationship and self-reported health. RESULTS: Age, SES, self-reported health status, sports activities and energy intake were the strongest predictors of BMI. The important outcome of this study is that the association between BMI and its predictors varies along the BMI distribution. Especially, energy intake, health status and SES were marginally associated with BMI in normal-weight subjects; this relationships became stronger in the range of overweight, and were strongest in the range of obesity. CONCLUSIONS: Predictors of BMI and the strength of these associations vary across the BMI distribution in German adults. Consequently, to identify predictors of BMI, the entire BMI distribution should be considered.

Determinants of consumption-day amounts applicable for the estimation of usual dietary intake with a short 24-h food list.

Next to the information on frequency of food consumption, information on consumption-day amounts is important to estimate usual dietary intake in epidemiological studies. Our objective was to identify determinants of consumption-day amounts to derive person-specific standard consumption-day amounts applicable for the estimation of usual dietary intake using separate sources to assesss information on consumption probability and amount consumed. 24-h Dietary recall data from the German National Nutrition Survey II (n = 8522; aged 20-80 years) conducted between 2005 and 2007 were analysed for determinants of consumption-day amounts of thirty-eight food and beverage groups using LASSO variable selection for linear mixed-effects models. Determinants included sex, age, BMI, smoking status, years of education, household net income, living status and employment status. Most often, sex, age and smoking status were selected as predictors for consumption-day amounts across thirty-eight food groups. In contrast, living with a partner, employment status and household net income were less frequently chosen. Overall, different determinants were of relevance for different food groups. The number of selected determinants ranged from eight for coffee and juice to zero for cabbage, tea, root vegetables, leafy vegetables, fruit vegetables, legumes, offal, vegetable oils, and other fats. For the estimation of usual dietary intake in a combined approach with a 24-h food list, person-specific standard consumption-day amounts could be used. Sex, age and smoking status were shown to be the most relevant predictors in our analysis. Their impact on the estimation of usual dietary intake needs to be evaluated in future studies.

Trends in food consumption and nutrient intake in Germany between 2006 and 2012: results of the German National Nutrition Monitoring (NEMONIT).

The German National Nutrition Monitoring (NEMONIT) is a longitudinal and nationwide study to assess changes in food consumption and nutrient intake in Germany. A sample of 1840 participants (baseline age: 14-80 years) was drawn from the nationally representative German National Nutrition Survey (NVS) II (2005-2007). The participants have been interviewed by telephone annually since 2008. Food consumption was assessed by two 24-h recalls in the NVS II and the 4 years of NEMONIT (2008-2012/2013), respectively. Energy and nutrient intakes were calculated using the German Nutrient Database 3.02. Diet quality was evaluated using the Healthy Eating Index-NVS (HEI-NVS) II. Time trends were analysed by generalised estimating equation. Consumption of fruit/fruit products and fruit juice/nectar among men and women decreased, whereas consumption of water, soft drinks and coffee/tea increased over the 6-year period. Furthermore, increased consumption of confectionery and animal fats was observed among women. HEI-NVS II did not change since NVS II in both sexes. There were no changes in energy and protein intakes, but carbohydrate intake declined while fat intake increased over time. Regarding micronutrients, a decreasing intake of thiamin, riboflavin and vitamin B6 was observed in both sexes, but intake of Mg, Fe and niacin increased among women over time. In conclusion, food consumption and nutrient intake remained relatively stable between 2005-2007 and 2012/2013 within this German cohort. A few favourable and unfavourable changes were observed. Compared with national dietary guidelines, consumption of food of plant origin remained too low and consumption of meat/meat products remained too high in Germany.

Food consumption of adults in Germany: results of the German National Nutrition Survey II based on diet history interviews.

The second German National Nutrition Survey (NVS II) aimed to evaluate food consumption and other aspects of nutritional behaviour of a representative sample of the German population, using a modular design with three different dietary assessment methods. To assess usual food consumption, 15,371 German speaking subjects 14-80 years of age completed a diet history interview between November 2005 and November 2006. With reference to the guidelines of the German Nutrition Society (DGE), NVS II observed that the German population did not eat enough foods of plant origin, especially vegetables and consumed too much of meat and meat products. While generally similar food consumption is observed in other European countries, consumption of bread, fruit juices/nectars and beer is higher in Germany. On average, men consumed two times more meat and soft drinks as well as six times more beer than women did, whereas the consumption of vegetables, fruit as well as herbal/fruit tea was higher in women. Older participants showed a lower consumption of meat, fruit juice/nectars, soft drinks and spirits as well as a higher consumption of fish, vegetables, fruit, and herbal/fruit tea than adolescents and younger adults did. There are also differences in food consumption with regard to socio-economic status (SES). Persons with higher SES consumed more vegetables, fruit, fish, water, coffee/tea and wine, while persons with lower SES consumed more meat and meat products, soft drinks and beer. In general, the food consumption of women, the elderly and the higher SES group tends to be closer to the official dietary guidelines in Germany.

Intake of dietary folate and folic acid in Germany based on different scenarios for food fortification with folic acid.

PURPOSE: Besides the adverse health effects of a low folate intake, the risks of high intakes of folic acid have moved into the focus. The aim of this study was to investigate the potential range of folate and folic acid intake of the German population under consideration of different fortification scenarios. METHODS: Food consumption data of 13,926 participants of the German National Nutrition Survey II (NVS II), collected with two 24-h recalls, were used to calculate the nutrient intake. The nutrient data are based on the German Nutrient Database (BLS), information from a market survey and analyses of multivitamin juices. The scenarios were modelled without, as well as with low and high fortification levels of folic acid. RESULTS: The median intake of dietary folate equivalents ranged from 191 µg/d (men) and 168 µg/d (women) without fortification to 425 µg/d (men) and 334 µg/d (women) in the highest fortification scenario. Thus, 12.4-68.2% (men) and 5.9-56.1% (women) met the 300 µg/d recommended by the nutrition societies of Germany, Austria and Switzerland. In the highest fortification scenario, 1.9% (men) and 0.8% (women) exceeded the tolerable upper intake level (UL) of 1,000 µg/d folic acid given by the European Food Safety Authority. For supplement users, this proportion was 5.2 and 5.4%. CONCLUSIONS: Only a high fortification of several foods leads to a marked increase of the proportion of population reaching the recommendation. Simultaneously, with a high fortification a higher proportion exceeds the UL, especially in combination with supplements.

Comparison of two dietary assessment methods by food consumption: results of the German National Nutrition Survey II.

PURPOSE: To further characterise the performance of the diet history method and the 24-h recalls method, both in an updated version, a comparison was conducted. METHODS: The National Nutrition Survey II, representative for Germany, assessed food consumption with both methods. The comparison was conducted in a sample of 9,968 participants aged 14-80. Besides calculating mean differences, statistical agreement measurements encompass Spearman and intraclass correlation coefficients, ranking participants in quartiles and the Bland-Altman method. RESULTS: Mean consumption of 12 out of 18 food groups was higher assessed with the diet history method. Three of these 12 food groups had a medium to large effect size (e.g., raw vegetables) and seven showed at least a small strength while there was basically no difference for coffee/tea or ice cream. Intraclass correlations were strong only for beverages (>0.50) and revealed the least correlation for vegetables (<0.20). Quartile classification of participants exhibited more than two-thirds being ranked in the same or adjacent quartile assessed by both methods. For every food group, Bland-Altman plots showed that the agreement of both methods weakened with increasing consumption. CONCLUSIONS: The cognitive effort essential for the diet history method to remember consumption of the past 4 weeks may be a source of inaccurateness, especially for inhomogeneous food groups. Additionally, social desirability gains significance. There is no assessment method without errors and attention to specific food groups is a critical issue with every method. Altogether, the 24-h recalls method applied in the presented study, offers advantages approximating food consumption as compared to the diet history method.

Degradation of folic acid in fortified vitamin juices during long term storage.

Folic acid (FA) concentrations of nine fortified vitamin juices were determined with the aim to study the FA degradation and to investigate the deviation from the declared label value. The juices were received shortly after bottling and were analyzed monthly during controlled storage conditions (light and dark) over one year. The analyses were performed by HPLC-MS/MS, which included a fast "dilute and shoot" sample preparation. Average decreases in FA concentration of 46% were observed after one year. Fresh juices (shortly after bottling) showed the highest deviations from the declared label value (up to+89%). Label values did not reflect the actual concentration of FA in these products, making it difficult to determine the intake of this vitamin.

Estimated dietary intakes and sources of flavanols in the German population (German National Nutrition Survey II).

BACKGROUND/OBJECTIVES: Data from intervention studies suggest a beneficial effect of flavanols on vascular health. However, insufficient data on their intake have delayed the assessment of their health benefits. The aim of this study was to estimate intake of flavanols and their main sources among people living in Germany. SUBJECTS/METHODS: Data from diet history interviews of the German National Nutrition Survey II for 15,371 people across Germany aged 14-80 years were analyzed. The FLAVIOLA Flavanol Food Composition Database was compiled using the latest US Department of Agriculture and Phenol-Explorer Databases and expanded to include recipes and retention factors. RESULTS: Mean intake of total flavanols, flavan-3-ol monomers, proanthocyanidins (PA), and theaflavins in Germany was 386, 120, 196, and 70 mg/day, respectively. Women had higher intakes of total flavanols (399 mg/day) than men (372 mg/day) in all age groups, with the exception of the elderly. Similar results were observed for monomers (108 mg/day for men, 131 mg/day for women) and PA (190 mg/day; 203 mg/day), although intake of theaflavins was higher in men (74 mg/day; 66 mg/day). There was an age gradient with an increase in total flavanols, monomers, and theaflavins across the age groups. The major contributor of total flavanols in all subjects was pome fruits (27%) followed by black tea (25%). CONCLUSIONS: This study demonstrated age- and sex-related variations in the intake and sources of dietary flavanols in Germany. The current analysis will provide a valuable tool in clarifying and confirming the potential health benefits of flavanols.

Estimation of dietary intake of bis(2-ethylhexyl)phthalate (DEHP) by consumption of food in the German population.

In the study presented here, we evaluated the exposure of the German population aged 14-80 years to bis(2-ethylhexyl)phthalate (DEHP) from consumption of food by means of deterministic and probabilistic estimations. The study was performed on the basis of an extensive review of literature from around the world reporting measured data on DEHP in food, as well as official German food control data. Only data from individual measurements were considered and used for fitting of distributions. A wide range of concentrations in non-representative samples are reported in the literature. On the basis of the available DEHP concentration data, 37 food categories were characterized which covered all major food classes. Food consumption data were taken from the diet history interviews of the German National Nutrition Survey II (Nationale Verzehrsstudie II) which was performed in 2005/2006 in a representative study population of 15,371 and is the most recent data source of this kind in Germany. Average DEHP intake was estimated deterministically using data on measured concentrations in food (medians and means) and food consumption (means). A total dietary exposure to DEHP of 3.6 (median based) and 9.3µg/kg of BW per day (based on mean values) was estimated deterministically. In addition, distributions of both concentrations and consumption figures were fitted using the @RISK best fit tool for further probabilistic estimations. This approach resulted in estimates within the same range: the estimated median DEHP intake in the whole population (both non-consumers and consumers of the foods considered) was 10.2, the arithmetic mean 14.0 and the 95th percentile 28.6µg/kg of BW per day. The respective estimates for consumers only were 12.4, 18.7 and 36.5µg/kg of BW per day. These results demonstrate that the probabilistic approach is able to estimate broader ranges of exposure even when using data representing an average intake. Moreover, it reflects the uncertainties of the estimation due to insufficient analytical data on concentrations of DEHP in food.

Relative validation of a food frequency questionnaire for national health and nutrition monitoring.

BACKGROUND: Validation of a food frequency questionnaire (FFQ) is important as incorrect information may lead to biased associations. Therefore the relative validity of an FFQ developed for use in the German Health Examination Survey for Adults 2008-2011 (DEGS) was examined. METHODS: Cross-sectional comparisons of food consumption data from the FFQ and from two 24-hour recalls were made in a sample of 161 participants (aged 18 to 80 years) of an ongoing nationwide survey, the German National Nutrition Monitoring (NEMONIT). The data collection took place from November 2008 to April 2009. RESULTS: Spearman rank correlations between the FFQ and the 24-hour dietary recalls ranged from 0.15 for pizza to 0.80 for tea, with two third of the correlation coefficients exceeding 0.30. All correlation coefficients were statistically significant except those for pizza and cooked vegetables. The proportion of participants classified into the same or adjacent quartile of intake assessed by both methods varied between 68% for cooked vegetables and 94% for coffee. There were no statistically significant differences in food consumption estimates between both methods for 38% of the food groups. For the other food groups, the estimates of food consumption by the FFQ were not generally higher or lower than estimates from the 24-hour dietary recalls. CONCLUSIONS: The FFQ appears to be reasonably valid in the assessment of food consumption of German adults. For some food groups, such as raw and cooked vegetables, relative risks estimates should be interpreted with caution because of the poor ranking agreement.