The MSM program: web-based statistics package for estimating usual dietary intake using the Multiple Source Method.

BACKGROUND/OBJECTIVES: The Multiple Source Method (MSM) is a new statistical method for estimating usual dietary intake including episodically consumed foods on the basis of two or more short-term measurements such as 24-h dietary recalls. Optional information regarding habitual use or non-use of a food can be included as a covariate in the model estimating the intake, as well as a parameter for identifying consumers and non-consumers. The objective was to implement the MSM algorithms into an easy-to-use statistical program package. SUBJECTS/METHODS: The implementation was realized as a web-based application using the Perl application framework Catalyst. As the engine for the statistical calculations, the R system was used. To allow simultaneous use of the program by different users, a multiuser system with a resource bag pattern design was implemented. RESULTS: We established a software program that implements the algorithms of the MSM and allows interactive usage of the method, using standard web technologies. The program is hosted on a website established at the DIFE and can be accessed at https://nugo.dife.de/msm. The communication between users and the program web site is encrypted, securing transmitted data against unauthorized use. Users can interactively import several data sets, define the analysis model, review and export results and graphs. The use of the program is supported by online help and a user guide. CONCLUSIONS: The MSM website provides a program package that allows nutritional scientists to calculate usual dietary intakes by combining short-term and long-term measurements (multiple sources). It promotes simple access to the MSM to estimate usual food intake for individuals and populations.

Comparing four methods to estimate usual intake distributions.

BACKGROUND/OBJECTIVES: The aim of this paper was to compare methods to estimate usual intake distributions of nutrients and foods. As 'true' usual intake distributions are not known in practice, the comparison was carried out through a simulation study, as well as empirically, by application to data from the European Food Consumption Validation (EFCOVAL) Study in which two 24-h dietary recalls (24-HDRs) and food frequency data were collected. The methods being compared were the Iowa State University Method (ISU), National Cancer Institute Method (NCI), Multiple Source Method (MSM) and Statistical Program for Age-adjusted Dietary Assessment (SPADE). SUBJECTS/METHODS: Simulation data were constructed with varying numbers of subjects (n), different values for the Box-Cox transformation parameter (λ(BC)) and different values for the ratio of the within- and between-person variance (r(var)). All data were analyzed with the four different methods and the estimated usual mean intake and selected percentiles were obtained. Moreover, the 2-day within-person mean was estimated as an additional 'method'. These five methods were compared in terms of the mean bias, which was calculated as the mean of the differences between the estimated value and the known true value. The application of data from the EFCOVAL Project included calculations of nutrients (that is, protein, potassium, protein density) and foods (that is, vegetables, fruit and fish). RESULTS: Overall, the mean bias of the ISU, NCI, MSM and SPADE Methods was small. However, for all methods, the mean bias and the variation of the bias increased with smaller sample size, higher variance ratios and with more pronounced departures from normality. Serious mean bias (especially in the 95th percentile) was seen using the NCI Method when r(var) = 9, λ(BC) = 0 and n = 1000. The ISU Method and MSM showed a somewhat higher s.d. of the bias compared with NCI and SPADE Methods, indicating a larger method uncertainty. Furthermore, whereas the ISU, NCI and SPADE Methods produced unimodal density functions by definition, MSM produced distributions with 'peaks', when sample size was small, because of the fact that the population's usual intake distribution was based on estimated individual usual intakes. The application to the EFCOVAL data showed that all estimates of the percentiles and mean were within 5% of each other for the three nutrients analyzed. For vegetables, fruit and fish, the differences were larger than that for nutrients, but overall the sample mean was estimated reasonably. CONCLUSIONS: The four methods that were compared seem to provide good estimates of the usual intake distribution of nutrients. Nevertheless, care needs to be taken when a nutrient has a high within-person variation or has a highly skewed distribution, and when the sample size is small. As the methods offer different features, practical reasons may exist to prefer one method over the other.

Eating out, weight and weight gain. A cross-sectional and prospective analysis in the context of the EPIC-PANACEA study.

OBJECTIVE: The aim of this study was to examine the association of body mass index (BMI) and weight gain with eating at restaurants and similar establishments or eating at work among 10 European countries of the European Prospective Investigation into Cancer and Nutrition (EPIC) study. SUBJECTS: This study included a representative sample of 24,310 randomly selected EPIC participants. METHODS: Single 24-h dietary recalls with information on the place of consumption were collected using standardized procedures between 1995 and 2000. Eating at restaurants was defined to include all eating and drinking occasions at restaurants, cafeterias, bars and fast food outlets. Eating at work included all eating and drinking occasions at the workplace. Associations between eating at restaurants or eating at work and BMI or annual weight changes were assessed using sex-specific linear mixed-effects models, controlling for potential confounders. RESULTS: In southern Europe energy intake at restaurants was higher than intake at work, whereas in northern Europe eating at work appeared to contribute more to the mean daily intake than eating at restaurants. Cross-sectionally, eating at restaurants was found to be positively associated with BMI only among men (ß=+0.24, P=0.003). Essentially no association was found between BMI and eating at work among both genders. In a prospective analysis among men, eating at restaurants was found to be positively, albeit nonsignificantly, associated with weight gain (ß=+0.05, P=0.368). No association was detected between energy intake at restaurants and weight changes, controlling for total energy intake. CONCLUSION: Among men, eating at restaurants and similar establishments was associated with higher BMI and possibly weight gain.

Use of dietary supplements in the European Prospective Investigation into Cancer and Nutrition calibration study.

BACKGROUND: Dietary supplement use is increasing, but there are few comparable data on supplement intakes and how they affect the nutrition and health of European consumers. The aim of this study was to describe the use of dietary supplements in subsamples of the 10 countries participating in the European Prospective Investigation into Cancer and Nutrition (EPIC). METHODS: Specific questions on dietary supplement use were asked as a part of single 24-h recalls performed on 36,034 men and women aged 35-74 years from 1995 to 2000. RESULTS: Between countries, the mean percentage of dietary supplement use varied almost 10-fold among women and even more among men. There was a clear north-south gradient in use, with a higher consumption in northern countries. The lowest crude mean percentage of use was found in Greece (2.0% among men, 6.7% among women), and the highest was in Denmark (51.0% among men, 65.8% among women). Use was higher in women than in men. Vitamins, minerals or combinations of them were the predominant types of supplements reported, but there were striking differences between countries. CONCLUSIONS: This study indicates that there are wide variations in supplement use in Europe, which may affect individual and population nutrient intakes. The results underline the need to monitor consumption of dietary supplements in Europe, as well as to evaluate the risks and benefits.