The focus of human nutrition research during the last decades has been to define the relationship between nutrient composition of the diet, food choices and health; however, a growing body of evidence suggests that meal patterns may explain part of the variation in diet-related disease outcomes between individuals( Reference Fabry, Hejl and Fodor 1 – Reference Titan, Bingham and Welch 3 ) and be a significant contributor to the obesity epidemic( Reference Mattes 4 – Reference Murakami and Livingstone 6 ). Meal patterns can broadly be defined as patterned structures of food and drink intake and comprise daily frequency of meals and snacks, temporal distribution of energy intake and consistency of eating behaviours( Reference Leech, Worsley and Timperio 7 – Reference Berg and Bertéus Forslund 9 ). There is evidence that frequency of meals and snacks and temporal distribution of energy intake are linked to cultural and environmental factors( Reference Oltersdorf, Schlettwein-gsell and Winkler 10 , Reference Wansink, Payne and Shimizu 11 ), metabolic responses( Reference Heden, Liu and Sims 12 , Reference Farshchi, Taylor and Macdonald 13 ) and circadian variations in appetite-regulating hormones and digestion( Reference de Castro 14 , Reference Hutchison and Heilbronn 15 ). Thus, there is an urgent need to examine the relative importance of meal patterns for metabolic risk factors and concurrent health in different populations in order to guide the development of evidence-based dietary policies.
Today, few European authorities provide public health recommendations on meal patterns and although advice on regular meals exists in some countries, specific recommendations on frequency or temporal distribution of meals and snacks are rarely included( Reference Berg and Bertéus Forslund 9 ). Further, in the latest revision of the Nordic Nutrition Recommendations from 2012( 16 ), the guideline on meal pattern from 2004 proposing one to three snacks daily( 17 ) was withdrawn without comment. The absence of recommendations is likely to be due to a lack of consistency in the current literature examining the importance of meal patterns for health parameters which, in part, can be explained by several recurring methodological problems. These problems include a wide range of assessment methods used to examine meal patterns, heterogeneity in how meal patterns are analysed, lack of a standardized terminology and small study samples in specific populations( Reference Leech, Worsley and Timperio 7 , Reference Bellisle 18 ). Hence, these limitations have obstructed the research field and made interpretation and comparability between studies and countries challenging. Therefore, there is a need to map differences in meal patterns using consistent methodology and terminology in large and diverse population samples to advance the research field and promote the development of dietary guidelines.
In the European Prospective Investigation into Cancer and Nutrition (EPIC) calibration study, standardized 24 h diet recalls were collected among approximately 37 000 participants from twenty-seven centres in ten European countries( Reference Slimani, Kaaks and Ferrari 19 ). Dietary data were consistently collected through computerized and harmonized interview software, allowing for a homogeneous comparison of dietary patterns across the European countries( Reference Slimani, Kaaks and Ferrari 19 , Reference Slimani, Deharveng and Charrondiere 20 ). Thus, in the light of the heterogeneous methodology traditionally used to assess and analyse meal patterns, the EPIC calibration study provides a unique opportunity to examine and describe differences in meal patterns across the European countries, which will be a valuable resource and benchmark for Europe. Hence, the aim of the current descriptive report was to characterize country- and centre-specific meal patterns in terms of daily intake frequency and temporal distribution of energy intake in the EPIC calibration study.
Methods
Study population
Data presented herein were derived from the EPIC calibration study which was nested within EPIC and performed during 1995–2000. The design, rationale and methodology of EPIC and the calibration study have been described in detail previously( Reference Slimani, Kaaks and Ferrari 19 , Reference Riboli, Hunt and Slimani 21 ). In short, EPIC is a multicentre prospective cohort study investigating the association between diet, lifestyle and cancer among approximately 520 000 participants across twenty-three administrative centres in ten European countries: Denmark, France, Germany, Greece, Italy, the Netherlands, Norway, Spain, Sweden and the UK. EPIC participants were recruited from the general population (Bilthoven (the Netherlands), Greece, Germany, Sweden, Denmark, Norway, Cambridge (UK), Spain and Italy), women undergoing breast cancer screening (Utrecht (the Netherlands), Florence (Italy)), members of a health insurance for school employees (France) and blood donors (some centres in Italy and Spain). In Oxford (UK), most of the participants (87 %) were vegetarians or vegans and/or had a special interest in health and are therefore evaluated separately (the ‘Health-conscious’ in contrast to the ‘General population’ from Cambridge). For descriptive dietary analyses, the original twenty-three administrative centres have been reclassified into twenty-seven centres according to their geographic region from which nineteen centres recruited both female and male participants and eight centres recruited women only (centres belonging to France, Norway, Utrecht (the Netherlands) and Naples (Italy)). The study began in 1992 and was approved by the ethical review boards of the International Agency for Research on Cancer (Lyon, France) and from all local recruiting institutes. Written informed consent was obtained from all participants.
Within EPIC, information on usual individual dietary intake was assessed using a country-specific diet history or FFQ( Reference Riboli, Hunt and Slimani 21 ). Thus, the EPIC calibration study was developed to correct for random and systematic errors in baseline dietary measurements and involved a single 24 h diet recall in a sub-sample of almost 37 000 participants to be used as the reference calibration method( Reference Slimani, Kaaks and Ferrari 19 , Reference Kaaks, Plummer and Riboli 22 , Reference Ferrari, Day and Boshuizen 23 ). The sub-sample represented approximately an 8 % stratified random sample of the total EPIC cohort and was weighted according to the cumulative numbers of cancer cases expected by sex and 5-year age strata. The results in the present report are based on dietary data from the standardized 24 h diet recall.
Assessment of dietary intake
Information on dietary intake in the calibration study was collected using a standardized computer-assisted and interviewer-administered software program (EPIC-SOFT) specifically designed to standardize the 24 h diet recall across the EPIC centres. The structure and functions of the software program have been described in detail elsewhere( Reference Slimani, Kaaks and Ferrari 19 , Reference Slimani, Deharveng and Charrondiere 20 ). In brief, the interview was structured into two steps: a first step where participants were asked to recall all foods and drinks consumed during the previous day, and a second step where they were asked to describe and quantify their intake. To standardize the memory aids used by the interviewer during the recall, eleven food consumption occasions (FCO) were predefined and asked for, and information on all foods and drinks consumed were entered as one of the following FCO according to the participant’s answer: (i) before breakfast, (ii) breakfast, (iii) during morning, (iv) before lunch, (v) lunch, (vi) after lunch, (vii) during afternoon, (viii) before dinner, (ix) dinner, (x) after dinner and (xi) during evening. These FCO were defined to chronologically cover the different occasions of consumption during the day and consider the different food habits among the participating countries. For each FCO, questions on time (per full hour) and place of consumption were asked as additional probes; thus, each FCO could be selected several times because of intakes in different hours (except for breakfast, lunch and dinner). The diet interview was conducted according to a ‘wake-up to wake-up’ approach with participants listing all foods and drinks consumed between waking up on the recall day to waking up on the interview day. However, the mean duration of the recalled day was always about 24 h across the centres and countries( Reference Slimani, Kaaks and Ferrari 19 ). Interviews were conducted over various seasons and days of the week, however; interviews with regard to diet on Saturdays were conducted on Mondays in most countries for logistical reasons. All participants provided the diet recall through face-to-face interviews, except in Norway where a telephone interview was conducted( Reference Brustad, Skeie and Braaten 24 ). Energy and nutrient intakes were calculated using the EPIC nutrient database which was developed to harmonize nutrient databases across the EPIC countries( Reference Deharveng, Charrondiere and Slimani 25 , Reference Slimani, Deharveng and Unwin 26 ).
Definitions used to analyse meal patterns
In the current report, all FCO are defined as separate intake occasions except for FCO consisting of water only (tap and mineral water), which were excluded. As a result, intake frequency describes the total number of intake occasions per day, which can consist of food only, drinks only or food and drinks combined. In order not to limit intake frequency to a maximum of eleven intake occasions per day, we included information on time per full hour to separate single FCO selected at numerous time points (e.g. FCO ‘during morning’ consumed at both 09.00 and 11.00 hours). No further criteria on time or energy intake were applied. Further, meals are defined as ‘breakfast’, ‘lunch’ and ‘dinner’ while all other FCO are defined as ‘snacks’. Thus, the following aspects of meal patterns are presented herein: daily intake frequency, the proportion reporting at least one intake occasion at each FCO and the absolute as well as relative energy contribution from meals and snacks.
Statistical analysis
Data are presented as mean and range, mean and standard error, and proportions stratified by sex, country and/or centre as indicated. Intake frequencies displayed in Fig. 1 are adjusted for age and weighted by season and day of the week using ANCOVA to account for over- and under-sampling across all countries. Consequently, the adjusted means represent the mean number of intake occasions per day of a population with balanced distribution of recalls over season, day of the week and the mean age of 55·3 years for women and 56·8 years for men. In addition to the main analysis, we also conducted sensitivity analysis to exclude over- and under-reporters of energy intake. This was performed by calculating the ratio of reported energy intake to estimated BMR taking age, sex, weight and height into account. The ratio of 1·55 was then used to calculate the confidence limits according to a 95 % confidence interval (lower and upper limit of <0·88 and >2·72, respectively). Ratios falling below or above the 95 % confidence limits were used to define the presence of misreporting( Reference Schofield 27 , Reference Goldberg, Black and Jebb 28 ). Although this method has poor sensitivity for identifying invalid reports of energy intake at the individual level from a single 24 h recall( Reference Black 29 ), it was considered sufficient to examine the potential influence of extreme misreporting on the overall results. Data were analysed using the statistical software package IBM SPSS Statistics Version 21.0.
Mean number of intake occasions per day, with their standard errors represented by vertical bars, by country and sex (
, women; 
, men), adjusted for age and weighted by season and day of dietary recall; European Prospective Investigation into Cancer and Nutrition (EPIC) calibration study
Results
Study participants
A total of 36 020 participants (22 985 women and 13 035 men) with dietary data from the 24 h diet recall were included in the current report after exclusion of participants aged under 35 or over 74 years due to low participation in these age groups (n 960) and individuals with incomplete information (n 14). Mean (range) age for women and men ranged from 49·0 (35·0–65·5) and 50·0 (35·2–65·2) years (Bilthoven, the Netherlands) to 61·4 (45·3–74·2) and 64·1 (50·5–74·3) years (Malmö, Sweden), respectively. Mean (range) BMI of women varied from 22·9 (14·4–37·6) (South of France, France) to 29·3 (17·9–48·8) kg/m2 (Granada, Spain) and from 23·9 (18·2–31·8) (UK Health-conscious) to 29·3 (20·9–46·2) kg/m2 (Granada, Spain) for men. Data on energy intake across the centres have been reported previously( Reference Ocke, Larranaga and Grioni 30 ).
Intake frequency across countries
After adjustment for age and weighting by season and day of recall, mean intake frequency for women ranged from 5·0 intake occasions/d in Greece and Italy to 7·0 intake occasions/d in the Netherlands. The corresponding numbers for men ranged from 4·9 in Italy to 6·8 in the UK General population (Fig. 1 and online supplementary material, Supplemental Table 1). There was a south–north gradient in intake frequency, with fewer intake occasions in the Mediterranean countries (Greece, Spain, Italy and France) compared with central European (Germany, the Netherlands and UK) and Nordic (Denmark, Sweden and Norway) countries. Also, in several countries there was a tendency for slightly higher intake frequency in women than in men. For snack frequency only, see Supplemental Table 2.
The proportion of women reporting at least one intake occasion at the specific food consumption occasions (FCO) and the average energy contribution from each FCO; European Prospective Investigation into Cancer and Nutrition (EPIC) calibration study
The proportion of men reporting at least one intake occasion at the specific food consumption occasions (FCO) and the average energy contribution from each FCO; European Prospective Investigation into Cancer and Nutrition (EPIC) calibration study
* Eight centres recruited women only (centres belonging to France, Norway, the Netherlands (Utrecht) and Italy (Naples)).
Intake occasions across countries and centres
Tables 1 and 2 give the proportion of women and men reporting at least one intake occasion at the eleven different FCO and the mean energy contribution from each FCO. As displayed in Tables 1 and 2, differences in meal patterns were found both across centres within the same country and across different countries, with the greatest heterogeneity for snack consumption. For example, the proportion of women having an intake occasion during the morning ranged from 31 % in the north and west of Norway to 90 % in Utrecht (the Netherlands). Further, the same discrepancy was seen during the afternoon with 30 % of women in the north and west of Norway and 93 % of women in Utrecht (the Netherlands) reporting an intake occasion. The corresponding numbers for men ranged from 38 % in Granada (Spain) to approximately 80 % in Bilthoven (the Netherlands) and the UK General population for intake occasions during the morning, and from 37 % in Murcia (Spain) to 89 % in Aarhus (Denmark) for intake occasions during the afternoon. Likewise, a south–north gradient appeared for intake occasions during the evening, with 2–33 % of women in Mediterranean countries, 49–87 % of women in central European countries and 73–77 % of women in Nordic countries reporting an intake occasion. The same was revealed for men reporting an intake occasion during the evening, with 2–30 %, 59–85 % and 78 % in Mediterranean, central European and Nordic countries, respectively. As for main meals, the majority of participants across all countries reported consumption of breakfast (range 85–100 %), lunch (range 76–100 %) and dinner (range 90–99 %); however, participants in central and northern European countries reported lunch to a somewhat lesser degree than did those in Mediterranean countries.
Likewise, geographical differences in meal patterns were also found within countries. In Spain, 37–38 % of women and men in Granada v. 60 % of women and men in San Sebastian reported an intake occasion during the morning. Moreover, 8–10 % of Italian women and men in Ragusa reported an intake occasion during the evening compared with 32–36 % in Turin. Finally, in Denmark, 66 % of women in Copenhagen reported an intake occasion during the evening compared with 91 % in Aarhus and this difference was also evident among Danish men (73 % v. 90 %, respectively).
Energy contribution of meals and snacks
Figures 2(a) and (b) (and online supplementary material, Supplemental Table 3) display the proportion of daily energy intake consumed as meals and snacks across countries. Breakfast contributed 11–19 % and 9–20 % of daily energy intake among women and men, respectively, across all countries. However, greater differences were revealed for lunch, which provided respectively 38–43 % and 41–45 % of daily energy intake for women and men within Mediterranean countries compared with 16–27 % and 20–26 % for women and men in central European and Nordic countries. Less pronounced differences were observed for dinner, which provided 24–37 % and 29–40 % of daily energy intake among women and men across all countries. Further, heterogeneity was also found for energy contribution of snacks with Mediterranean countries consuming 13–20 % (women) and 10–17 % (men) of daily energy intake as snacks while the corresponding numbers were 24–34 % (women) and 23–35 % (men) in central and northern European countries. Figure 3 illustrates the overall differences in proportional distribution of daily energy intake across meals and snacks between Mediterranean, central European and Nordic countries with women and men combined as no major differences were found between sexes.
Proportion of daily energy intake consumed as breakfast, lunch, dinner and snacks by country (
, Greece; 
, Spain; 
, Italy; 
, France; 
, Germany; 
, the Netherlands; 
, UK – General population; 
, UK – Health conscious; 
, Denmark; 
, Sweden; 
, Norway) and sex: (a) women and (b) men; European Prospective Investigation into Cancer and Nutrition (EPIC) calibration study
The proportion of daily energy intake consumed as breakfast, lunch, dinner and snacks in (a) Mediterranean, (b) central European and (c) Nordic countries for women and men combined; European Prospective Investigation into Cancer and Nutrition (EPIC) calibration study
Sensitivity analysis
In general, mean energy intake from each intake occasion and the proportion reporting an intake occasion at each FCO increased slightly for both women and men after the exclusion of misreporters (see online supplementary material, Supplemental Tables 4 and 5). Similarly, mean intake frequency was increased by 0–0·2 intake occasions/d for women and 0–0·1 intake occasions/d for men across all countries after exclusion of misreporters.
Discussion
In the present report we aimed to characterize and compare meal patterns across ten European countries participating in the EPIC calibration study, taking advantage of the harmonized and detailed data collection across all the regions. We found pronounced geographical differences in meal structures both across countries and across centres within the same country. In general, a trend emerged that lunch provided a greater proportion of total energy intake in Mediterranean countries compared with central and northern European countries. In contrast, greater proportions of participants in central and northern countries reported intake occasions in between main meals and larger energy contributions of snacks, compared with participants in Mediterranean countries.
There is currently a discussion whether regular and socially shared meals are becoming increasingly rare and if grazing meal patterns, characterized by frequent snacking, are taking the place of traditional meals and dissolving collective norms guiding temporal eating( Reference Lund and Gronow 31 , Reference Lhuissier, Tichit and Caillavet 32 ). In the present report, we examined meal patterns during 1995–2000 in an adult European population aged 35–74 years and found that most countries still shared uniformity in the three-meal-a-day pattern at that time, with a high proportion reporting consumption of breakfast, lunch and dinner across all countries, even though lunch was less frequently reported in Nordic and central European countries than in Mediterranean countries. This three-meal continuity has also been reported in more recent studies in Nordic( Reference Lund and Gronow 31 ), French( Reference Lhuissier, Tichit and Caillavet 32 – Reference Pettinger, Holdsworth and Gerber 34 ) and Flemish( Reference Mestdag 35 ) populations. However, for most central and northern countries, snacks contributed more to daily energy intake than did breakfast or lunch and in some countries snacks contributed nearly as much energy as did dinner. Still, for Mediterranean countries in general and for Italy and France in particular, snacks contributed significantly less energy than did lunch and dinner, indicating a preserved tradition in these regions for main meals to provide the majority of daily energy intake. Nevertheless, as these data were collected 15–20 years ago, more recent shifts in meal patterns remain to be explored.
Although we found the three-meal pattern to be widespread across Europe, we demonstrated different distributions of energy intake across the main meals. For example, a south–north gradient was found for lunch with Mediterranean countries consuming a greater proportion of their daily energy intake at lunch compared with central and northern countries. This gradient was also reported in the SENECA study (Survey in Europe on Nutrition and the Elderly; a Concerted Action), where meal patterns among 2600 elderly participants from twelve European countries were assessed in 1988–1989( Reference Schlettwein-gsell, Decarli and de Groot 36 , Reference de Groot and van Staveren 37 ). In that study, lunch contributed 45–48 % of daily energy intake in Italy and France compared with 21–33 % in northern and central Europe. The authors also found that total energy intake among women was higher in centres where energy contribution of lunch was low( Reference Schlettwein-gsell, Decarli and de Groot 36 ). As studies have reported evening meals to be less satiating than morning meals and glucose tolerance and insulin secretion to decrease over the day( Reference Berg and Bertéus Forslund 9 , Reference de Castro 14 , Reference Jakubowicz, Barnea and Wainstein 38 ), consuming a high proportion of total energy intake at lunch has been suggested to compose an additional positive component of the Mediterranean diet when looking beyond the solely nutritive aspects( Reference Hoffman and Gerber 39 ). Further, as previous research has found snacking and high intake frequency to be positively associated with energy intake and overweight and obesity( Reference Mattes 4 , Reference Murakami and Livingstone 6 ), absence of snacking might be yet another favourable component of the Mediterranean diet. However, aspects such as meal times and timing of snacks need to be further explored in order to fully characterize differences in temporal distribution of energy intake across Europe. In sum, future research should consider if the beneficial effects of the Mediterranean diet are possibly also mediated by a meal pattern with a greater energy contribution from lunch and less from snacking by widening the scope of dietary surveys to include assessment of meal structures and temporal distribution of energy intake.
We reported high intake frequency in northern and central Europe, with participants in the UK and the Netherlands consuming an average of 6–7 intake occasions/d. Prominent snacking among the Dutch was also reported in the SENECA study where 31–32 % of daily energy intake was derived from snacks and in the latest Dutch national food consumption survey from 2007–2010 (30 % of daily energy intake from snacks)( 40 ), similar to the 34–35 % in the EPIC cohort. Further, the SENECA study also found a low energy contribution of snacks among Mediterranean countries at 6–8 % in France and Italy( Reference Schlettwein-gsell, Decarli and de Groot 36 , Reference de Groot and van Staveren 37 ) compared with 10–13 % in the EPIC cohort. The consequences of different intake frequencies are a hot topic within the research field, dividing scientists into opposing opinions. On one hand, snacks have been reported to be less nutritive, more energy dense and more motivated by social and/or cultural drivers than by biological energy needs compared with meals( Reference Mattes 4 , Reference Ovaskainen, Reinivuo and Tapanainen 41 ). Hence, this would suggest that transition to grazing meal patterns might have negative health consequences given the risk for overconsumption of energy intake. On the other hand, snacks have the potential to increase the opportunity for healthy, nutrient-dense foods such as fruit and fibre-rich grains( Reference Hartmann, Siegrist and van der Horst 42 – Reference Kong, Beresford and Alfano 44 ). In addition, gender differences have been suggested such that women are more likely to make healthier food choices while men more often choose sweets, savouries and sugar-sweetened drinks( Reference Hartmann, Siegrist and van der Horst 42 ). Also, as energy compensation for drinks has been demonstrated to be weak in comparison to solid foods( Reference Houchins, Tan and Campbell 45 , Reference Houchins, Burgess and Campbell 46 ), the effect of drinks consumed as snacks warrants further exploration. Thus, there is a need to characterize not only the frequency but also the quality of snacks, especially in countries and populations where people derive high percentages of energy through snacks, as snacks have the potential to improve overall dietary intake and impact health.
The strengths of the present report include a large and diverse population sample across several European countries concurrent with standardized and homogeneous methodology which enabled an objective assessment and comparison of meal patterns across a broad geographical span. However, there are some limitations to the report. First, populations included in EPIC are not nationally representative samples of the European general population( Reference Slimani, Kaaks and Ferrari 19 ) and younger adults may have different meal patterns from those reported here. Nevertheless, data may still reveal significant geographical differences in meal pattern due to the broad range of participating countries and harmonized methodology used. Second, one 24 h diet recall does not provide data at the individual level; however, due to the large sample size, trends in proportions consuming various intake occasions across the day should still appear. Third, under-reporting of energy intake is a limitation within all self-reported dietary assessments and a previous EPIC report found that under-reporting was more prevalent among women and participants with overweight and obesity( Reference Ferrari, Slimani and Ciampi 47 ). Thus, as under-reporting has been reported to affect both energy intake and intake occasions( Reference Bellisle 8 , Reference Freisling, van Bakel and Biessy 48 ), intake frequencies and proportions are likely to be underestimated as demonstrated by the slight increase when misreporters were excluded in the sensitivity analysis. Fourth, as the predefined FCO enabled only three main meals to be reported, foods considered to be consumed as a main meal beyond the three predefined meals have been classified as snacks herein. Thus, this could influence the interpretation of meal and snack patterns in countries where traditionally four meals are considered ‘main meals’ as for example in Norway (breakfast, lunch, dinner and evening meal). Also, as no predefined time or energy content criteria for each FCO were provided to participants, classification of FCO may thus not be strictly objective. However, the lack of studies using a common approach in European settings strengthens the rationale of this work and its potential to provide more guidance to improve future research. Finally, considering these data are now 15–20 years old, differences in meal patterns reported here need to be confirmed in more recent data; still, the present study provides a valuable resource and benchmark for studying trends in Europe.
Conclusion
We examined meal patterns in a large-scale study across ten European countries. 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, currently and over time, across various cultures and populations could provide critical context to research efforts to characterize the relationships between dietary intake and health.
Acknowledgements
Financial support: The coordination of EPIC is financially supported by the European Commission (DG-SANCO) and the International Agency for Research on Cancer. The national cohorts are supported by Danish Cancer Society (Denmark); Ligue Contre le Cancer, Institut Gustave Roussy, Mutuelle Générale de l’Education Nationale, Institut National de la Santé et de la Recherche Médicale (INSERM) (France); German Cancer Aid, German Cancer Research Center (DKFZ), Federal Ministry of Education and Research (BMBF), Deutsche Krebshilfe, Deutsches Krebsforschungszentrum and Federal Ministry of Education and Research (Germany); the Hellenic Health Foundation (Greece); Associazione Italiana per la Ricerca sul Cancro–AIRC–Italy and National Research Council (Italy); Dutch Ministry of Public Health, Welfare and Sports (VWS), Netherlands Cancer Registry (NKR), LK Research Funds, Dutch Prevention Funds, Dutch ZON (Zorg Onderzoek Nederland), World Cancer Research Fund (WCRF), Statistics Netherlands (The Netherlands); ERC-2009-AdG 232997 and Nordforsk, Nordic Centre of Excellence programme on Food, Nutrition and Health (Norway); Health Research Fund (FIS), PI13/00061 to Granada, PI13/01162 to EPIC-Murcia, Regional Governments of Andalucía, Asturias, Basque Country, Murcia and Navarra, ISCIII RETIC (RD06/0020) (Spain); Swedish Cancer Society, Swedish Research Council and County Councils of Skåne and Västerbotten (Sweden); Cancer Research UK (14136 to EPIC-Norfolk; C570/A16491 and C8221/A19170 to EPIC-Oxford), Medical Research Council (1000143 to EPIC-Norfolk, MR/M012190/1 to EPIC-Oxford) (United Kingdom). The funders had no role in the design, analysis or writing of this article. For information on how to submit an application for gaining access to EPIC data and/or biospecimens, please follow the instructions at http://epic.iarc.fr/access/index.php. Conflict of interest: None. Authorship: A.W. and H.B.F. initiated the study. E.H., A.W. and H.B.F. formulated the research questions, performed the analysis and wrote the manuscript taking into account comments from all co-authors. N.S., M.K. P., H.F., H.B., G.B., L.S. and E.W. contributed to the conception, analysis and interpretation of the data and drafting of the manuscript. All other co-authors were local EPIC collaborators involved in the collection of dietary data and other data. All authors read and approved the final version. Ethics of human subject participation: The study was approved by the ethical review boards of the International Agency for Research on Cancer (Lyon, France) and from all local recruiting institutes. Written informed consent was obtained from all participants.
Supplementary material
To view supplementary material for this article, please visit http://dx.doi.org/10.1017/S1368980016001142
