Food photographs in nutritional surveillance: errors in portion size estimation using drawings of bread and photographs of margarine and beverages consumption

Food photographs are widely used as instruments to estimate portion sizes of consumed foods. Several food atlases are available, all developed to be used in a specific context and for a given study population. Frequently, food photographs are adopted for use in other studies with a different context or another study population. In the present study, errors in portion size estimation of bread, margarine on bread and beverages by two-dimensional models used in the context of a Belgian food consumption survey are investigated. A sample of 111 men and women (age 45–65 years) were invited for breakfast; two test groups were created. One group was asked to estimate portion sizes of consumed foods using photographs 1–2 d after consumption, and a second group was asked the same after 4 d. Also, real-time assessment of portion sizes using photographs was performed. At the group level, large overestimation of margarine, acceptable underestimation of bread and only small estimation errors for beverages were found. Women tended to have smaller estimation errors for bread and margarine compared with men, while the opposite was found for beverages. Surprisingly, no major difference in estimation error was found after 4 d compared with 1–2 d. Individual estimation errors were large for all foods. The results from the present study suggest that the use of food photographs for portion size estimation of bread and beverages is acceptable for use in nutrition surveys. For photographs of margarine on bread, further validation using smaller amounts corresponding to actual consumption is recommended

24-hour dietary recalls as reference calibration measurements in EPIC: from statistical theory to epidemiological application

Large multi-centre cohort studies have been set up with the aim of increasing the statistical power to detect an association between diet and disease by including study populations varying both in dietary exposures and outcome diseases. However, such studies raise also new statistical and methodological challenges to improve the comparability of dietary measurements collected from populations from different geographical and socio-cultural origins. In the European Prospective Investigation into Cancer and Nutrition (EPIC), involving half a million subjects from 23 centres in 10 European countries, a calibration approach was adopted to correct for systematic errors in individual dietary measurements obtained by means of different dietary assessment methods across centres, by re-expressing them according to the same reference scale (between-cohort calibration). 24-hour diet recall was selected as the reference calibration method in EPIC. In order to meet the theoretical requirements, such a reference calibration method must be highly standardized across study centres, provide accurate dietary estimates at the population level and should not be an obstacle to the collection of data from a representative sub-sample of the entire cohort. This thesis deals with translating the theoretical statistical concept of the calibration into an epidemiological application in the context of a large multi-centre study on diet and cancer.The thesis presents first some theoretical concepts of the main sources of measurement errors associated with the 24-hour diet recall method and the standardisation procedures used to prevent or minimize them in the context of a large multi-centre study. An ad hoc face-to-face computerized 24-hour diet recall interview programme (EPIC-SOFT) is then described as the end product used as reference calibration method across the EPIC centres. The rationale and a new theoretical concept of standardizing food composition tables in large multi-centre studies such as EPIC is discussed separately. In a second part, the design and the populations of the calibration sub-studies set up in each EPIC centre are described, as well as the representativeness of the calibration sub-sample compared to the whole cohort.In order to estimate the degree of standardisation of the 24-hour diet recalls across interviewers an analysis of variance was performed using mean total energy per interviewer as dependent variable. Furthermore, a validation study using urinary nitrogen as independent reference measurements was conducted to estimate the reliability of mean 24-hour diet recall measurements of protein (and total energy) for between-cohort calibration. Finally, the 36,900 24-hour recalls collected in EPIC were used to study the large heterogeneity in dietary patterns existing between the EPIC centres, using the same detailed dietary methodology.This was the first time that calibration sub-studies using the same dietary methodology has been set up in a large multi-centre European study. Despite inherent methodological and practical problems, the calibration worked well in a large multi-centre setting, and the calibration sub-sample can reasonably be considered to be representative of the entire EPIC cohort in most centres. The standardisation across interviewers and the validation of 24-hour diet recalls for between-cohort calibration shown encouraging results. However, measurement errors, particularly conscious or unconscious behaviour of respondents and/or interviewers, cannot be prevented entirely, and the problem of measurement errors and its determinants need to be considered in the application of the calibration, as well as day of the week and seasonal coverage. This first experience should also lead to additional improvements in the reference method and setting up nested calibration sub-studies in the future. Furthermore, it demonstrates that standardized dietary methodologies can be developed in an international context and opens perspectives for using the EPIC-SOFT programme or other approaches in large European nutritional studies

Major Differences in Diet across Three Linguistic Regions of Switzerland: Results from the First National Nutrition Survey menuCH.

Switzerland is a multilingual country located between Germany, France and Italy, which differ by dietary habits and related outcomes. We explored differences in food consumption as well as compliance to the Swiss food-based dietary guidelines (FBDG) across the German-, French-, and Italian-speaking regions. The 2014-2015 nationwide cross-sectional survey was conducted among a stratified random sample of 2057 adults aged 18 to 75 years. Trained dietitians assessed food consumption via two non-consecutive 24-h dietary recalls using the international validated software GloboDiet <sup>®</sup> . Recorded foods and beverages were classified into six groups and 31 subgroups relevant for assessing compliance to the FBDG (Swiss Food Pyramid). Usual daily intake distributions were modelled and weighted for sampling design, non-response, weekdays and season. Participation rate was 38%. Significant differences across regions were observed in 18 of 31 food subgroups ( <i>p</i> ≤ 0.01). Weighted mean daily intakes in the German-, French- and Italian-speaking regions were, respectively, 245 g, 155 g, 140 g for soft drinks, 273 g, 214 g, 135 g for coffee, 127 g, 72 g, 109 g for milk, 32 g, 45 g, 43 g for red meat, 18 g, 29 g, 34 g for fish/seafood, 8.1 g, 6.4 g, 3.7 g for butter, and 206 g, 214 g, 168 g for vegetables. The seven FBDGs were followed by <1% of the population. Four in 10 participants met ≥3 FBDG. Eighteen percent of participants ate ≥5 portions of fruit and vegetables a day, without regional differences. Food consumption substantially differed across the three linguistic regions of Switzerland. Adherence to FBDG was uniformly low. This highlights the potential influence of culture on diet. Nutritional education along with public health interventions are needed and may be most efficient if regionally targeted

Predicting urinary creatinine excretion and its usefulness to identify incomplete 24h urine collections

Studies using 24 h urine collections need to incorporate ways to validate the completeness of the urine samples. Models to predict urinary creatinine excretion (UCE) have been developed for this purpose; however, information on their usefulness to identify incomplete urine collections is limited. We aimed to develop a model for predicting UCE and to assess the performance of a creatinine index using para-aminobenzoic acid (PABA) as a reference. Data were taken from the European Food Consumption Validation study comprising two non-consecutive 24 h urine collections from 600 subjects in five European countries. Data from one collection were used to build a multiple linear regression model to predict UCE, and data from the other collection were used for performance testing of a creatinine index-based strategy to identify incomplete collections. Multiple linear regression (n 458) of UCE showed a significant positive association for body weight (ß = 0·07), the interaction term sex × weight (ß = 0·09, reference women) and protein intake (ß = 0·02). A significant negative association was found for age (ß = - 0·09) and sex (ß = - 3·14, reference women). An index of observed-to-predicted creatinine resulted in a sensitivity to identify incomplete collections of 0·06 (95 % CI 0·01, 0·20) and 0·11 (95 % CI 0·03, 0·22) in men and women, respectively. Specificity was 0·97 (95 % CI 0·97, 0·98) in men and 0·98 (95 % CI 0·98, 0·99) in women. The present study shows that UCE can be predicted from weight, age and sex. However, the results revealed that a creatinine index based on these predictions is not sufficiently sensitive to exclude incomplete 24 h urine collections

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, coordinated 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

Multi-time-scale hydroclimate dynamics of a regional watershed and links to large-scale atmospheric circulation:Application to the Seine river catchment, France

(IF 3.73; Q1)International audienceIn the present context of global changes, considerable efforts have been deployed by the hydrological scientific community to improve our understanding of the impacts of climate fluctuations on water resources. Both observational and modeling studies have been extensively employed to characterize hydrological changes and trends, assess the impact of climate variability or provide future scenarios of water resources. In the aim of a better understanding of hydrological changes, it is of crucial importance to determine how and to what extent trends and long-term oscillations detectable in hydrological variables are linked to global climate oscillations.In this work, we develop an approach associating correlation between large and local scales, empirical statistical downscaling and wavelet multiresolution decomposition of monthly precipitation and streamflow over the Seine river watershed, and the North Atlantic sea level pressure (SLP) in order to gain additional insights on the atmospheric patterns associated with the regional hydrology. We hypothesized that: (i) atmospheric patterns may change according to the different temporal wavelengths defining the variability of the signals; and (ii) definition of those hydrological/circulation relationships for each temporal wavelength may improve the determination of large-scale predictors of local variations.The results showed that the links between large and local scales were not necessarily constant according to time-scale (i.e. for the different frequencies characterizing the signals), resulting in changing spatial patterns across scales. This was then taken into account by developing an empirical statistical downscaling (ESD) modeling approach, which integrated discrete wavelet multiresolution analysis for reconstructing monthly regional hydrometeorological processes (predictand: precipitation and streamflow on the Seine river catchment) based on a large-scale predictor (SLP over the Euro-Atlantic sector). This approach basically consisted in three steps: 1 – decomposing large-scale climate and hydrological signals (SLP field, precipitation or streamflow) using discrete wavelet multiresolution analysis, 2 – generating a statistical downscaling model per time-scale, 3 – summing up all scale-dependent models in order to obtain a final reconstruction of the predictand. The results obtained revealed a significant improvement of the reconstructions for both precipitation and streamflow when using the multiresolution ESD model instead of basic ESD. In particular, the multiresolution ESD model handled very well the significant changes in variance through time observed in either precipitation or streamflow. For instance, the post-1980 period, which had been characterized by particularly high amplitudes in interannual-to-interdecadal variability associated with alternating flood and extremely low-flow/drought periods (e.g., winter/spring 2001, summer 2003), could not be reconstructed without integrating wavelet multiresolution analysis into the model. In accordance with previous studies, the wavelet components detected in SLP, precipitation and streamflow on interannual to interdecadal time-scales could be interpreted in terms of influence of the Gulf-Stream oceanic front on atmospheric circulation

Physical activity reduces the risk of incident type 2 diabetes in general and in abdominally lean and obese men and women: the EPIC-InterAct Study.

AIMS/HYPOTHESIS: We examined the independent and combined associations of physical activity and obesity with incident type 2 diabetes in men and women. METHODS: The InterAct case-cohort study consists of 12,403 incident type 2 diabetes cases and a randomly selected subcohort of 16,154 individuals, drawn from a total cohort of 340,234 participants with 3.99 million person-years of follow-up. Physical activity was assessed by a four-category index. Obesity was measured by BMI and waist circumference (WC). Associations between physical activity, obesity and case-ascertained incident type 2 diabetes were analysed by Cox regression after adjusting for educational level, smoking status, alcohol consumption and energy intake. In combined analyses, individuals were stratified according to physical activity level, BMI and WC. RESULTS: A one-category difference in physical activity (equivalent to approximately 460 and 365 kJ/day in men and women, respectively) was independently associated with a 13% (HR 0.87, 95% CI 0.80, 0.94) and 7% (HR 0.93, 95% CI 0.89, 0.98) relative reduction in the risk of type 2 diabetes in men and women, respectively. Lower levels of physical activity were associated with an increased risk of diabetes across all strata of BMI. Comparing inactive with active individuals, the HRs were 1.44 (95% CI 1.11, 1.87) and 1.38 (95% CI 1.17, 1.62) in abdominally lean and obese inactive men, respectively, and 1.57 (95% CI 1.19, 2.07) and 1.19 (95% CI 1.01, 1.39) in abdominally lean and obese inactive women, respectively. CONCLUSIONS/INTERPRETATION: Physical activity is associated with a reduction in the risk of developing type 2 diabetes across BMI categories in men and women, as well as in abdominally lean and obese men and women

Main nutrient patterns and colorectal cancer risk in the European Prospective Investigation into Cancer and Nutrition study.

BACKGROUND: Much of the current literature on diet-colorectal cancer (CRC) associations focused on studies of single foods/nutrients, whereas less is known about nutrient patterns. We investigated the association between major nutrient patterns and CRC risk in participants of the European Prospective Investigation into Cancer and Nutrition (EPIC) study. METHODS: Among 477 312 participants, intakes of 23 nutrients were estimated from validated dietary questionnaires. Using results from a previous principal component (PC) analysis, four major nutrient patterns were identified. Hazard ratios (HRs) and 95% confidence intervals (CIs) were computed for the association of each of the four patterns and CRC incidence using multivariate Cox proportional hazards models with adjustment for established CRC risk factors. RESULTS: During an average of 11 years of follow-up, 4517 incident cases of CRC were documented. A nutrient pattern characterised by high intakes of vitamins and minerals was inversely associated with CRC (HR per 1 s.d.=0.94, 95% CI: 0.92-0.98) as was a pattern characterised by total protein, riboflavin, phosphorus and calcium (HR (1 s.d.)=0.96, 95% CI: 0.93-0.99). The remaining two patterns were not significantly associated with CRC risk. CONCLUSIONS: Analysing nutrient patterns may improve our understanding of how groups of nutrients relate to CRC

Développement d’un spectre à risque uniforme pour la région d’Alger

Cet article présente l’évaluation de l’aléa sismique en terme d’accélération spectrale (SA) dans la région d’Alger en utilisant la méthode probabiliste (PSHA) En général, les résultats attendus de l’étude d’Aléa sismique est de fournir les accélérations maximales de calcul pour une période de retour donnée. Dans ce travail, on s’intéresse au développement de spectre à risque uniforme (UHS), outil nécessaire pour tout calcul au séisme des ouvrages tenant en compte les sources sismiques aussi bien du champ proche et du champ lointain, de tel spectres fournissent les accélérations spectrales pour un éventail de période de structures et pour un nivaux de risque uniforme (100 et 500 ans).L’analyse des incertitudes effectuée, montre l’importance du choix de ou des lois d’atténuation à utiliser