Voedingsmiddelenanalyses van de Afdeling Humane Voeding: Deel 15. Vetzuursamenstelling van bakkerijmargarines in Nederland 2008

In 2008 werd de vetzuursamenstelling van bakkerijmargarines onderzocht met als doel de voortgang in verbetering van de vetzuursamenstelling in deze producten in beeld te brengen ten opzichte van eerdere bemonsteringen in 1996 en 2004. De vetzuursamenstelling van 14 A-merken bakkerijmargarines afkomstig van drie fabrikanten werd onderzocht. De margarines waren van het type “korst”, “crème”, “wals” of “cake”. De vetzuursamenstelling verschilde nauwelijks tussen de verschillende typen margarine, noch tussen producten van verschillende fabrikanten. Het gehalte verzadigde vetzuren bedroeg gemiddeld 41 g / 100 g product (range: 38–48 g); het gehalte trans-vetzuren was gemiddeld 1 g / 100 g product (range

Fat and non-absorbable fat and the regulation of food intake

The effects of consumption of meals with differences in energy-, fat-, protein-, carbohydrate-content, and physical state on subsequent dietary intake and feelings of appetite, were investigated in eight different studies. The main objective was to study whether or not humans compensate for the covert and overt energy differences, obtained by replacement of fat by a fat-replacer, in both the short (1 day) and long term (12 days). As fat-replacer the non-absorbable sucrose polyester (SPE) was used. A second objective was to investigate some methodological issues of research on food intake regulation.In normal weight men and women little compensation was found for the energy differences after the different meals. In all eight studies, mean energy compensation was less than 50% for both men and women, with an average for all studies of 14%, based upon a meta-analysis. No substantial differences in the level of energy compensation were found between men and women, or between the short and long term studies.Independent of the level of energy compensation, no macronutrient specific compensation was found. This means that the macronutrient composition of the subsequent dietary intake was similar after each meal manipulation. As a result the consumption of SPE lead to a decrease in daily fat intake.When artificial products (i.e. unidentifiable formula products) were given to the subjects, lower energy levels resulted in higher hunger ratings. When the energy manipulations were carried out with normal food products, small or no differences in feelings of appetite were found.The three macronutrients (fat, carbohydrate, protein) were equally satiating, and solid products were more satiating than liquid products.It is concluded that normal weight men and women do not, or poorly recognize covert energy differences between meals, and poorly adjust their food intake of subsequent meals after both covert and overt energy manipulations. Therefore the replacement of fat by a non-absorbable fat-replacer such as SPE can help to reduce both the daily energy and fat intake in normal weight humans.</p

An analytical comparison of the patient-to-doctor policy and the doctor-to-patient policy in the outpatient clinic

Outpatient clinics traditionally organize processes such that the doctor remains in a consultation room, while patients visit for consultation, we call this the Patient-to-Doctor policy. A different approach is the Doctor-to-Patient policy, whereby the doctor travels between multiple consultation rooms, in which patients prepare for their consultation. In the latter approach, the doctor saves time by consulting fully prepared patients. We compare the two policies via a queueing theoretic and a discrete-event simulation approach. We analytically show that the Doctor-to-Patient policy is superior to the Patient-to-Doctor policy under the condition that the doctor’s travel time between rooms is lower than the patient’s preparation time. Simulation results indicate that the same applies when the average travel time is lower than the average preparation time. In addition, to calculate the required number of consultation rooms in the Doctor-to-Patient policy, we provide an expression for the fraction of consultations that are in immediate succession; or, in other words, the fraction of time the next patient is prepared and ready, immediately after a doctor finishes a consultation.We apply our methods for a range of distributions and parameters and to a case study in a medium-sized general hospital that inspired this research

The impact of school size reduction on the development of academic skills in rural primary schools

Basisscholen aan de ‘randen’ van Nederland krimpen al geruime tijd in leerlingenaantallen. Doordat basisscholen kleiner worden, de onderwijscontext ongunstiger wordt en hoog opgeleide ouders wegtrekken staat de onderwijskwaliteit onder druk en zouden de leerprestaties kunnen dalen. Met dit surveyonderzoek is de ontwikkeling van leerprestaties in een krimpgebied onderzocht en nagegaan of de ernst van de krimp en sociaaleconomische achtergrond van leerlingen hier invloed op hebben. De data zijn afkomstig van schooladministratie- en leerlingvolgsystemen van bijna 1600 leerlingen op 24 reguliere basisscholen in Oost-Groningen. Gevonden is dat de gemiddelde vaardigheidsscores voor rekenen-wiskunde, begrijpend en technisch lezen licht fluctueren rondom de landelijke norm in de midden- en bovenbouw. Meerniveau groeicurve-analyses tonen de veerkracht van de basisscholen. Bij een minder goede leerlingencohort wordt de aanvankelijke achterstand weggewerkt totdat er in groep 8 geen noemenswaardige verschillen meer zijn met de andere leerlingcohorten. Ook de relatief ongunstige sociaaleconomische achtergrond van leerlingen en de mate van krimp vormen geen belemmering voor de ontwikkeling van de leerprestaties. Aanvankelijke lagere leerprestaties worden te niet gedaan, ongeacht de ernst van de krimp waarmee de school geconfronteerd wordt. Basisscholen in het krimpgebied Oost-Groningen weten voldoende te anticiperen op de ernstige gevolgen van krimp.Because of school size reduction, less favorable educational context and migration of high educated parents it is assumed that student achievement levels are gradually decreasing in rural areas. We studied the development of mathematics, reading comprehension and language decoding skills and whether this is influenced by the severity of school size reduction. Longitudinal data of 1600 pupils of 24 Dutch rural primary schools are used. Their average achievement level in grade one (6-7 year-olds), three-four, and six fluctuated slightly around thenational average. Multilevel polynomial growth models show that in case of an underachieving cohort at grade one the lag of development is gradually eliminated, regardless of the severity the school size reduction. In grade six all pupil cohorts attain a similar level. Dutch primary schools in a rural area are able to react effectively to the severe consequences of the reducing school size

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

Up and beyond: Building a mountain in the Netherlands

We discuss the idea of building a 2 km high mountain in the Netherlands. In this paper, we give suggestions on three important areas for the completion of this project. Issues like location, structure and sustainability are investigated and discussed in detail

The development of an intervention programme to reduce whole-body vibration exposure at work induced by a change in behaviour: a study protocol

<p>Abstract</p> <p>Background</p> <p>Whole body vibration (WBV) exposure at work is common and studies found evidence that this exposure might cause low back pain (LBP). A recent review concluded there is a lack of evidence of effective strategies to reduce WBV exposure. Most research in this field is focussed on the technical implications, although changing behaviour towards WBV exposure might be promising as well. Therefore, we developed an intervention programme to reduce WBV exposure in a population of drivers with the emphasis on a change in behaviour of driver and employer. The hypothesis is that an effective reduction in WBV exposure, in time, will lead to a reduction in LBP as WBV exposure is a proxy for an increased risk of LBP.</p> <p>Methods/Design</p> <p>The intervention programme was developed specifically for the drivers of vibrating vehicles and their employers. The intervention programme will be based on the most important determinants of WBV exposure as track conditions, driving speed, quality of the seat, etc. By increasing knowledge and skills towards changing these determinants, the attitude, social influence and self-efficacy (ASE) of both drivers and employers will be affected having an effect on the level of exposure. We used the well-known ASE model to develop an intervention programme aiming at a change or the intention to change behaviour towards WBV exposure. The developed programme consists of: individual health surveillance, an information brochure, an informative presentation and a report of the performed field measurements.</p> <p>Discussion</p> <p>The study protocol described is advantageous as the intervention program actively tries to change behaviour towards WBV exposure. The near future will show if this intervention program is effective by showing a decrease in WBV exposure.</p

Validating fatty acid intake as estimated by an FFQ : how does the 24 h recall perform as reference method compared with the duplicate portion?

Objective: To compare the performance of the commonly used 24 h recall (24hR) with the more distinct duplicate portion (DP) as reference method for validation of fatty acid intake estimated with an FFQ. Design: Intakes of SFA, MUFA, n-3 fatty acids and linoleic acid (LA) were estimated by chemical analysis of two DP and by on average five 24hR and two FFQ. Plasma n-3 fatty acids and LA were used to objectively compare ranking of individuals based on DP and 24hR. Multivariate measurement error models were used to estimate validity coefficients and attenuation factors for the FFQ with the DP and 24hR as reference methods. Setting: Wageningen, the Netherlands. Subjects: Ninety-two men and 106 women (aged 20–70 years). Results: Validity coefficients for the fatty acid estimates by the FFQ tended to be lower when using the DP as reference method compared with the 24hR. Attenuation factors for the FFQ tended to be slightly higher based on the DP than those based on the 24hR as reference method. Furthermore, when using plasma fatty acids as reference, the DP showed comparable to slightly better ranking of participants according to their intake of n-3 fatty acids (0·33) and n-3:LA (0·34) than the 24hR (0·22 and 0·24, respectively). Conclusions: The 24hR gives only slightly different results compared with the distinctive but less feasible DP, therefore use of the 24hR seems appropriate as the reference method for FFQ validation of fatty acid intake.</p