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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 (Β0.24, P0.003). 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 (Β0.05, P0.368). 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. © 2011 Macmillan Publishers Limited All rights reserved.

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. European Journal of Clinical Nutrition (2009) 63, S226-S238; doi: 10.1038/ejcn.2009.83

The kinetics of the reaction of dimethyl carbonate (DMC) and phenol to methyl phenyl carbonate (MPC) and the subsequent disproportion and transesterification reaction of methyl phenyl carbonate (MPC) to diphenyl carbonate (DPC) have been studied. Experiments were carried out in a closed batch reactor in the temperature range from 160 to 200 °C for initial reactant ratios of DMC/phenol from 0.25 to 3 and varying catalyst (titanium-(n-butoxide)) concentrations. The concept of a closed, ideally stirred, isothermal batch reactor incorporating an activity based reaction rate model has been used to fit kinetic parameters to the experimental data taking into account the catalyst concentration, the initial reactant ratio DMC/phenol and the temperature.

Diphenyl carbonate (DPC) is a precursor in the production of Polycarbonate (PC), a widely employed engineering plastic. To overcome the drawbacks of the traditional PC process - e.g. phosgene as a reactant and methylene chloride as solvent- a new process route starting from Dimethyl carbonate (DMC) via Methyl Phenyl carbonate (MPC) to DPC is investigated in this thesis. First the general applicability of activities in reaction rate equations is examined, both theoretically and experimentally, for the system CO2-OH—salts. The results show that the activity based reaction rate yields fundamentally better results compared to the traditional concentration based approach and moreover establishes a fundamental link to the activity based description of chemical equilibria. For the derivation of activity based reaction kinetics as well as chemical equilibria, activity coefficients are required. Hence, available VLE data of relevant carbonate systems has been taken from literature to fit corresponding UNIFAC parameters which have subsequently been used for the description of the relevant chemical equilibria and reaction kinetics. The chemical equilibria encountered in the process from DMC to DPC have been experimentally determined thereby studying the influence of the molar reactant ratio DMC/phenol (0.25-3.0) and temperature (160-200C). The activity based and concentration based chemical equilibria have been compared to each other and the temperature dependence of the chemical equilibria has been described. A comprehensive study has been performed to determine the kinetics of the three reactions involved in the carbonate system. The influence of the reactant ratio DMC/phenol (0.25-3.0), temperature (160-200C) and the catalyst amount has been investigated. The concept of a closed ideally stirred, isothermal batch reactor incorporating an activity based reaction rate model, has been used to fit kinetic parameters to the experimental data. For exploring the industrial production process of DPC from DMC using reactive distillation, a tray column model originating from the software package ChemSep was used. The influence of various parameters - feed location(s), number of stages, temperature and pressure - was studied and the results are evaluated. First a process comprising of one reactive distillation column and then a process employing two reactive distillation columns has been investigated.

The applicability of utilizing activities instead of concentrations in kinetic expressions has been investigated using the reaction of CO2 in sodium hydroxide solutions also containing different neutral salts (LiCl, KCl and NaCl) as model system. For hydroxide systems it is known that when the reaction rate constant is based on the use of concentrations in the kinetic expression, this “constant” depends both on the counter-ion in the solution and the ionic strength which is probably caused by the strong non-ideal behavior of various components in the solution. In this study absorption rate experiments have been carried out in the pseudo-first-order absorption rate regime. The experiments have been interpreted using a new activity based kinetic rate expression instead of the traditional concentration-based rate expression. A series of CO2 absorption experiments in different NaOH (1, 1.5, 2moll-1 )–salt (LiCl, NaCl or KCl)–water mixtures has been carried out, using salt concentrations of 0.5 and 1,5moll-1 all at a temperature of 298 K. Interpretation of the data additionally required the use of an appropriate equilibrium model (needed for the calculation of the activity coefficients), for which, in this case, the Pitzer model was used. The additions of the salts proved to have a major effect on the observed absorption rate. The experiments were evaluated with the traditional concentration based-approach and the “new” approach utilizing activity coefficients. With the traditional approach, there is a significant influence of the counter-ion and the hydroxide concentration on the reaction rate. The evaluation of the experiments with the “new” approach—i.e. incorporating activity coefficients in the reaction rate expressions—reduced the influence of the counter-ion and the hydroxide concentration on the reaction rate constant considerably. The absolute value of the activity based-reaction rate constant [...] for sodium hydroxide solutions containing either LiCl, KCl or NaCl is in the range between 10 000 and 15 000 kg (kmol-1 s-1) compared to the traditional approach where the value of the lumped reaction rate constant kOH is between 7000 and 34 000 m3 (kmol-1 s-1). Therefore, it can be concluded that the application of the new methodology is thought to be very beneficial especially in processes where “the thermodynamics meet the kinetics”. Based on this it is anticipated that the new kinetic approach will first find its major application in the modeling of integrated processes like Reactive Distillation, Reactive Absorption and Reactive Extraction processes where both, thermodynamics and kinetics, are of essential importance and, additionally, activity coefficients deviate substantially from unity.

The applicability of utilizing activities instead of concentrations in kinetic expressions has been investigated using the reaction of CO2 in sodium hydroxide solutions also containing different neutral salts (LiCl, KCl and NaCl) as model system. For hydroxide systems it is known that when the reaction rate constant is based on the use of concentrations in the kinetic expression, this “constant” depends both on the counterion in the solution and the ionic strength which is probably caused by the strong non-ideal behavior of various components in the solution. In this study absorption rate experiments have been carried out in the pseudo-first-order absorption rate regime. The experiments have been interpreted using a new activity based kinetic rate expression instead of the traditional concentration-based rate expression. A series of CO2 absorption experiments in different NaOH (1, 1.5, 2.0 mol l−1)–salt (LiCl, NaCl or KCl)–water mixtures has been carried out, using salt concentrations of 0.5 and 1.5 mol l−1 all at a temperature of 298 K. Interpretation of the data additionally required the use of an appropriate equilibrium model (needed for the calculation of the activity coefficients), for which, in this case, the Pitzer model was used. The additions of the salts proved to have a major effect on the observed absorption rate. The experiments were evaluated with the traditional concentration based-approach and the “new” approach utilizing activity coefficients. With the traditional approach, there is a significant influence of the counter-ion and the hydroxide concentration on the reaction rate. The evaluation of the experiments with the “new” approach—i.e. incorporating activity coefficients in the reaction rate expressions—reduced the influence of the counter-ion and the hydroxide concentration on the reaction rate constant considerably. The absolute value of the activity based-reaction rate constant kmOH−(γ) for sodium hydroxide solutions containing either LiCl, KCl or NaCl is in the range between 10 000 and 15 000 kg (kmol−1 s−1) compared to the traditional approach where the value of the lumped reaction rate constant kOH− is between 7000 and 34 000m3 (kmol−1 s−1). Therefore, it can be concluded that the application of the new methodology is thought to be very beneficial especially in processes where “the thermodynamics meet the kinetics”. Based on this it is anticipated that the new kinetic approach will first find its major application in the modeling of integrated processes like Reactive Distillation, Reactive Absorption and Reactive Extraction processes where both, thermodynamics and kinetics, are of essential importance and, additionally, activity coefficients deviate substantially from unity.