Saturday, December 22, 2007

Physical environmental factors do predict specific physical activities; an N=2 study

In the last decade it has been posited that the so-called obesogenic environment is the main driving force behind the obesity epidemic. Experts claim that our environment characterised by an over-abundant availability of palatable energy-dense foods that can be eaten anywhere and anytime, as well as lack of opportunities to be physically active make people eat too much calories and burn too little calories, leading to unnecessary weight gain and eventually to overweight and obesity. However, the scientific evidence for the hypothesis that physical environmental factors predict eating and physical activity behaviours is not yet strong, probably due to a lack of well-designed studies. Over the past few years we have conducted a series of systematic reviews on the availbale studies on associations between environmental factors and different nutrition behaviours and physical activity. These reviews (of mostly cross-sectional studies, using weak measurement instruments and often failing to adjust for possible confounding factors) indicated that the evidence was not yet strong. Only for very few associations was convincing and consistent evidence found, and the evidence for social environmental determinants of health behaviours was much stronger than for physical environmental factors. Recent studies further indicate that individual factors such as motivation and abilities remain important predictors of health behaviours. (See a list of links to the pubmed abstracts of the scientific papers on these reviews later in this message). However, today I did an N=2 study that illustrated that physical environmental circumstances can determine specific forms of physical activity, if motivation and ablities are taken care of. For the first time this year the ice on a few canals in the Netherlands was strong enough to allow ice skating on natural ice. We have had a few days of frost now, and although the ice is hardly reliable yet, many Dutch grabed their skates and went for it (some did get wet). My wife and I found a nice stretch of great ice a bit north of Haarlem. The icy environment allowed us to act on our motivation and to use our abilities!

Friday, December 21, 2007

A drink before the Christmas break

On Thursday afternoon, December 20, the EMGO Institute met for an informal drink at the café attached to the VU University medical center. This was a great occasion to look back at a good year for the EMGO institute ( . We had good scientific accomplishments with more than 20 PhD theses, Over 300 publications in Science Citation Index or Social Science Citation Index journals, and good acquisition of projects that will ensure scientific output for the years to come.
Our societal impact was also of good quality with policy and media attention for many of our projects, for example regarding e-health interventions, patient safety research, childhood obesity, and studies on environmental determinants of health lifestyles.
The year to come also looks good, with many interesting ongoing projects within our four research tracks, and some very interesting opportunities for additional research projects. One of these opportunities is research to test physical activity and training programs for cancer patients to build evidence based cancer rehabilitation programs, in collaboration with and supported by Alp-dhuzes ( This is a yearly sponsored cycling event on the Alp D’Huez mountain to raise money for cancer research. I get back on this topic in the weeks to come.
Another important event in the coming year will be the preparation and probabale start of an interfaculty research institute together with partners from the faculty of Psychology and Education and the faculty of Earth and Life Sciences.
The next week I will celebrate Christmas with family and friends and then go to Norway for some days to do cross country skiing.
I wish you all a very merry Christmas and a great new year.

Saturday, December 15, 2007

Prevention of unnecessary weight gain at the worksite

Yesterday Lydia Kwak defended her PhD thesis at a public meeting at Maastricht University. Her thesis describes the development, implementation and evaluation of an intervention program aiming to contribute to prevention of unnecessary weight gain among employees. Her PhD research was part of the NHS-NRG project, a comprehensive project funded by the Netherlands Heart Foundation on obesity prevention. This project consisted of two studies exploring behavioural, cognitive and environmental determinants of weight gain and energy-balance related behaviours, and three intervention studies; one aimed at adolescents (the Do-IT intervention), one for elderly people (the WAAG-study), and the one Lydia used for her PhD thesis which was called the In-Balance study.
Lydia Kwak used the Intervention Mapping protocol to develop the intervention that consisted of health education, self monitoring and environmental change components. The evaluation study used a controlled design and the results indicated that employees in intervention worksites had a lower fat mass at follow-up than employees of control worksites where the intervention program was not implemented. Her studies also showed the difficulties to convince worksites to participate in such an important study and to convince employees to participate in weight gain prevention activities. Prevention of weight gain should be key in attempts to curb the obesity epidemic, since treatment of obesity is hardly ever successful on the loner run.
Lydia Kwak’s thesis studies have been published in different international scientific journals. See for example:

Sunday, December 9, 2007

How can we evaluate national health promotion campaigns?

In the Netherlands as in many other countries, we invest in promotion of healthful and safe behaviours to contribute to prevention of chronic disease, accidents, et cetera. One of the ways to contribute to promotion of healthy lifestyles are so-called national campaigns, that often make use of mass media to communicate health promotion messages to the population at large.

Such campaigns should be evaluated to study if these campaigns indeed contribute to more healthful lifestyles among the population, i.e. we should study if money and other resources allocated to such campaigns are well spend.

A valid evaluation of national campaigns is not easy. The strongest research design to evaluate the effects of interventions is the so-called randomized controlled trial (RCT). RCTs are considered the most reliable form of scientific evidence in healthcare because they eliminate spurious causality and bias. RCTs are mainly used in clinical studies, but are also employed in other sectors such as judicial, educational, and social research. As their name suggests, RCTs involve the random allocation of different interventions (or treatments) to subjects or respondents/participants. This ensures that confounding factors are evenly distributed between treatment groups.

However, in evaluation of national campaigns randomization is not possible and a control group is not available because the population at large is exposed to the intervention.

Many national campaigns are therefore evaluated by means of a very simple design with one before and one after measurement. This often means that before and after the campaign is launched a sample of the target population is surveyed on the behaviour the campaign is addressing. If the after-campaign survey shows better results, this is supposed to indicate that the campaign was successful. The weakness of this research design can be illustrated with an example. The first picture next to this blog message shows the results of such before and after campaign measures related to the introduction of a bicycle helmet law in Australia. Before wearing a helmet became compulsory the number of head injuries was much higher than after. Conclusion: making people wear helmets prevents head injuries!? The second picture shows that this was not the case. In this picture not one before and one after campaign measurement was used, but a whole series of before and after measurements. This is called an interrupted time-series design. This picture shows that the reduction in head injuries was already ongoing before the helmet law was introduced, that this downward trend was continued after the law was in place. The picture indicates that the law did not change this trend in any way. Conclusion: the bicycle helmet law had no effect at all on head injuries.

The interrupted time series design is generally regarded as best-practice in evaluation of national campaigns or other circumstances where a control group is not possible. The Dutch Health Council recently published an advice on evaluation of national campaigns in which this was confirmed ( However, such an interrupted time-series design requires careful and timely planning of evaluation, additional resources to do the extra measurements, and expertise for statistical analyses of time series data. Time, extra resources and specialized statistical expertise is not always available for the organizations that develop and implement the campaigns, and these organizations feel that interrupted time-series design may be the best but not a realistic option for them. Furthermore, evaluation of national campaigns may not always need to be concerned with effects in terms of lifestyle behaviour changes, but sometimes evaluation in terms of reach, adoption, implementation or maintenance (see RE-AIM framework, of campaign activities may be sufficient, and such evaluations may require different research designs.

The Netherlands Organisation for Health Care Research and Development, ZonMW ( has ask me to further explore best and realistic practice in evaluations of national campaigns in the Netherlands. In the few months interviews will be held with representatives of all the organizations in the Netherlands that organize and implement national campaigns to learn about their evaluation goals, barriers and wishes for improvements.

Sinterklaas day with the Board of the VU University Medical Center

Five December is Sinterklaas day in the Netherlands (see for detailled information in Ducth, and for information in English). Sinterklaas or Sint Nicolaas (Saint Nicolaus) was a bishop from Myra in present day Turkey during early Christianity. His remains were abducted to Bari in southern Italian where a very beautiful Roman Sinterklaas church can be found. But the Dutch Sinterklaas legend tells us that Sinterklaas comes from Spain to the Netherlands with his ‘Moor’ servants (‘Zwarte Pieten’), bringing all children who have been good presents and treats. The story goes that the Coca Cola company adopted this wonderful celebration, transferred it to Christmas, and created Santa Claus, a kind of weak and stupid looking cousin of the real Sinterklaas.
This year I spend Sinterklaas day and night in the castle-hotel Vanenburg ( The board of the VU University Medical Center ( had invited the heads of the six Divisions to discuss such issues as the VUmc’s mission, the key stakeholders that the VUmc wishes to serve, and necessary human resource management to fulfil the mission.
For me it was a great opportunity to get to know the chairs of the other Divisions a little better and to join in fruitful discussions on VUmc’s ambitions (yes, we do wish to get better in what we do in health care, education and research) and the way we wish to realise these ambitions.

Thursday, December 6, 2007

Professors of Human Nutrition and food industry leaders and the nutrition policy of the Dutch government

The ministry of Health invited a bunch of nutrition professors and some representatives of the Dutch food industry to talk about its plans for nutrition policy in the years to come.
The discussion was based on four statements that were each introduced by two of the participants. These statements all concerned what the business sector, i.e. the food industry, retail and other point-of-choice settings can contribute to more healthful nutrition habits in the Netherlands. Like any other ‘western’ country, the Dutch eat too much, too much saturated fat and salt, and not enough fibre-rich foods.
The Dutch ministry of health as well as the representatives of the food industry, but also some of the nutrition professors appeared to have great confidence in the potential contribution of the food industry to promote more healthful diets. Product innovation should be key!
I have much less trust in the industry to really contribute to healthy eating. I think that business primarily want to sell the illusion of health, so that consumers can eat (more of) their products without feeling bad. Advertisements for foods, including foods that are high in calories, saturated fat, sugar and/or salt often promise suggestive health effects or healthful attributes that are very similar to what was promised in tobacco advertisements in the 1950s (see pictures).

I do believe that we need food innovation and involvement of the food industry next to other stakeholder is health promotion and health protection aimed at more healthful diets in the Netherlands. But this will only happen if the Dutch (or European) government sets strict and specific rules related to health claims, food labels, marketing and product enrichments. The European Community has tightened its rules on health claims, which is a good start.

Sunday, November 25, 2007

...and use a step counter to promote walking...

Last Wednesday I referred to a systematic review in the Britisch Medical Journal showing that well-planned intervention to promote walking can indeed encourage people to walk an extra 30-60 minutes per week. A study published in the Journal of the American Medical Association (JAMA; see shows that using step counters to self monitor walking activity encourages people to walk more. The authors, Bravata and colleagues, reviewed 26 original studies and their review indicates that using step counters on average leads to an extra 2000 steps per day (15-20 minutes walking). This extra activity was associated with a few kilo's less body weight and a lower blood pressure. See for an abstract of the review study.

Thursday, November 22, 2007

Walking review

Physical activity is part of a health energy-balanced lifestyle, and may contribute to weight management. Walking is a daily physical activity of moderate intensity that can be done almost anywhere and by anyone. Oglivie and colleagues published a systematic review of intervention to promote walking in the Britsh Medical Journal (BMJ 2007;334:1204, electronic prepub;
Their review indicates that the most successful interventions could increase walking by up to 30-60 minutes a week. This may not seem like much, but if we could induce such changes in the population it would contribute substantially to prevention of unnecessary weight gain. However, the evidence was mostly concerned the short term only, and the evidence is mostly based on isolated studies, and the authors conclude that studies are needed on true effectiveness in real-life situations.

Wednesday, November 14, 2007

Is being overweight good for you?

On November 2 I participated in a radio debate organised by radio Netherlands, the Dutch world service ( The debate was inspired by a book called 'Diet Nation: exposing the obesity crusade' ( The first author of the book, Patrick Basham (, participated in the debate, and he claims that the danger of being overweight is wildly over-estimated. According to Basham, the present “hysteria” about fatness is the result of alarmist lobby groups and bad science. He provides evidence indicating that people who are thin have lower life expectancy than people who are overweight.
Basham is right in claiming that being a bit overweight is not that bad for health. But obesity, i.e. being grossly overweight is, and on the road to obesity one passes through different stages of being a bit, than a bit more, and more and more extra bodyweight. Time trend research shows that people generally gain between 0.5 and 1 kg per year, and over the course of a few decades this does lead to health-threatening levels of obesity.
Basham claims that lobby groups, including the dieting industry, exaggerate the dangers of being overweight. Although I am sure that the lobby of the food industry to encourage people to eat more than they need is much stronger than the weight-loss industry, it is true that most dieting/weight loss strategies that are commercially marketed do not work in the long run. Almost all diets do lead to weight loss if people comply to the rules and regulations prescribed, but most diets are hard to maintain and such diets are often not well-varied and maintenance is therefore too difficult and if maintained such diets may lead to unhealthy nutrition. People who do loose weight generally regain the kilos soon enough when they stop dieting and start eating their ‘normal’ diet again. In order to curb the obesity epidemic we should therefore not focus on promoting weight loss among people who are somewhat overweight. We should focus on promotion of health eating and plenty of physical activity to help to prevent further weight gain and to promote physical fitness. It is better to be fit and somewhat overweight than unfit and lean. The HOPE project (Health promotion through Obesity Prevention in Europe) is dedicated to informing obesity prevention efforts:

Sunday, November 11, 2007

Body@Work and a new professor of occupational health.

On Thursday November 8, Dr. Allard van der Beek held his inaugural address to accept his chair in occupational health. His address was preceded by a symposium reporting on the Body@Work project (, a collaboration between the EMGO institute ( and TNO Quality of Life ( to support an conduct research on physical activity, work and health.
Professor Allard van der Beek argued in favour of carefully planned and evaluated preventive occupational health care in order to develop better interventions and improve evidence-based practice. He further argued that such research to develop preventive occupational health interventions should be especially focussed on opening the ‘epidemiological black box’, i.e. to gain better understanding on why and how certain behaviours are associated with work disability, and on intervention mapping (, i.e. to carefully tailor interventions to specific needs and characteristics of the target population. Such research is dependent on multidisciplinary collaborations.Allard also completed his first marathon recently…

Saturday, November 3, 2007

Towards an interfaculty research institute for health and care research.

Yesterday the senior staff of EMGO research institute (see met to discuss plans to reform our institute into a so-called interfaculty research institute. Our mission is to encourage, initiate, conduct, and publish excellent research of international standing to improve public and occupational health, primary care, rehabilitation, and long-term care.
The main challenges in these research fields all require interdisciplinary research, involving medical doctors as well as health scientists, psychologists et cetera. This asks for close collaborations between experts from different university faculties.
Our policy day was focussed on exactly that: what are the strengths, weaknesses, opprtunities and threats related to forming a formal interfaculty research institute, involving the VU University Medical Center (, the Institute for Health Sciences ( of the faculty of earth and life sciences and the faculty of psychology and education ( Other collaborations are with the faculty of Social Sciences ( and the faculty of Law
Important examples of ongoing interfaculty collaboration include the Netherlands Study on Depression and Anxiety NESDA ( as well as the longitudinal Aging Study Amsterdam (

Monday, October 29, 2007

Nutrition and cancer?

This week the new report from the World Cancer Research Fund on the association between nutrition, physical activity and cancer will be published (see This report is the result of one of the most comprehensive series of systematic reviews and meta analyses. The title of the new report is Food, Nutrition, Physical Activity and the Prevention of Cancer.

In a process that has taken five years, an expert panel of 21 renowned scientists from around the world reviewed and assessed the body of research on the relationship between food, nutrition (including obesity) physical activity and cancer risk. The expert panel has drawn conclusions based on this evidence and developed 10 health recommendations for the prevention of cancer.

Based on early ecological studies and case-control studies it was hypothesized that nutritional factors such as fat intake, fiber intake and fruit and vegetable consumption were strong determinants of risk for certain cancers.
In the last decades more and more longitudinal cohort studies have become available, and these studies show that the association between diet and cancer risk appears to be much weaker than was believed from the earlier weaker designed investigations.

However, the WCRF reviews will probably also make clear that obesity is a major risk factor for certain cancers, such as breast cancer.

Registration for the meeting where the new report will be launched is still possible…

Thursday, October 18, 2007

Be Active 07: Physical activity research conference in Adelaide Australia.

The last few days I attended the Be Active 07 conference in Adelaide ( This conference was in fact a combination of several conferences, sports medicine, injury prevention, and physical activity, with the possibility of attending sessions in each and a few joint sessions. I was invited to speak in the physical activity part on environmental determinants of physical activity. The short version of my talk is that physical activity is certainly not only influenced by physical environmental factors. Personal factors like motivation and abilities and social environmental factors like social support and positive examples of others, are of great importance, and are supported by stronger scientific evidence. In short, physical activity is a result of motivation, ability, opportunity and support. People will be most likely to be active if the are motivated to do so, if the have the right abilities, if their environment offers good opportunities and if the get support from relevant others. A short interview in the Herald Sun exaggerated my point a bit…(see
Steve Blair gave a very entertaining keynote on the ‘fit and fat’ message (see for example, He presented convincing evidence that physical activity has strong health benefits, also independent of weight loss, and that people who are fat but fit are much better of health-wise that lean but unfit people. He also presented nice research showing that physical activity is a more effective and less expensive treatment of conditions such as metabolic syndrome and hypertension that most other usual treatments. So why is it that physical activity support is not part of treatment programs and often not covered by health insurance?
Part of the program focussed on sedentary behaviours. Earlier studies have indicated that sedentary behaviour and physical activity are rather independent, i.e. people who are active may also engage in much sedentary behaviours. Earlier studies have also indicated that sedentary behaviour is an independent and maybe even more important determinants of conditions such as obesity and metabolic syndrome. Now some evidence was presented that just getting people out of their seats for a little while during their sedentary days may have a significant impact on prevention of such chronic conditions.

Wednesday, October 10, 2007

Visiting C-PAN at Deakin University, Melbourne Australia

This week I am a guest at the Behavioural Epidemiology group of the Centre for Physical Activity and Nutrition Research (C-PAN; please see, Deakin University, Melbourne Australia. This group really does work of great interest to ring behavioural nutrition and physical activity research a few steps further. In their work on explaining and promoting healthful nutrition and physical activity behaviours, they have adopted a social ecological perspective, and a main focus is on social and physical environmental determinants of these behaviours. Socio-economic differences in these behaviours is another topic that they excel in. Their studies include children and adults, observational and intervention studies. Productive as they are, they appear rather relaxed, taking plenty of time to discuss their work, but also making sure that I am well-fed and that I have a bike during my stay to attend to my cycling addiction. The groups is led by professor David Crawford and Drs. Jo Salmon, Kylie Ball and Anna Timperio. You should check out their work, for example via pubmed (see ).
Although you see quite some cyclists in Melbourne, I suspect that these are the really dedicated few. The cycling infrastructure is not that good. There are some very nice bike routes, especially the main Yarra trail, along the Yarra river, but cycling for transport is something else. Not many designated bike lanes, and if you do encounter one, they are often used to park cars…See and for more information on cycling in Melbourne and the Melbourne city bike plan.

Monday, October 8, 2007

A new chair in epidemiology of common mental disorders

On Friday October 5, Professor Brenda Penninx gave her inaugural address for her new position as professor of epidemiology of common mental disorders. Professor Penninx coordinates the Netherlands Study of Depression and Anxiety disorders, a large-scale and unique longitudinal study primarily focussed on two of the most common mental disorders: depression and anxiety disorders. During her address, Brenda Penninx provided a clear overview of some recent results from this ongoing study and her plans for further research in the years to come. She touched upon her research showing the associations between these mental disorders and other important burdens of disease, such as cardiovascular conditions, as well as with lifestyle determinants such as nutrition, physical activity and smoking habits. A few years ago she received a VIDI grant for her work from the Netherlands organisation for Scientific Research, NWO, one of the most prestigious grants available (see and se is also a member of the ‘Young Academy of the Netherlands Academy of the Royal Dutch Academy of Arts and Sciences (see and Professor Penninx work is part of the Common Mental Disorders program of the EMGO Institute, and her work illustrates very nicely the fruitful interdisciplinary and interfaculty collaboration within our institute. She works with colleagues from the Psychiatry, Clinical Psychology and General Practitioners departments in mapping causes and effects of common mental disorders, and in exploring and evaluating ways for prevention and early treatment.

Friday, October 5, 2007

A new website to facilitate healthy lifestyle promotion in primary schools in the Netherlands

Last Wednesday the Netherlands Heart Foundation, the Netherlands Nutrition Foundation and the Netherlands Dairy Foundation launched a new web portal to help policy makers, school boards, teachers and parents to make sense out of the great variety of instruments, interventions and educational materials that are meant to contribute to school-based health promotion (see; ‘gezonderwijs’ is Dutch for healthy and smart) .
A symposium with parents, teachers, schoolchildren, policy makers and scientists was held to describe and illustrate why such a portal is useful, and to discuss different avenues for promoting healthful nutrition and physical activity habits among primary schoolchildren. I was one of the speakers. I congratulated the organisers with their initiative but also argued that a web portal with health education possibilities will not be enough to ensure healthy behaviours among our youth; environmental changes are needed. One of the teachers showed a very nice example. The picture shows the school playing ground that was transformed into a multiple sports arena.
Another interesting thing was that the Netherlands Dairy Foundation was one of the initiators. Is this a good public-private partnership to promote health, or another illustration of how ‘objective’ health education and food marketing are intertwined?

Friday, September 28, 2007

Watching TV, using computers, body weight and promotion of healthy lifestyles

More and more studies point out that watching TV, using your computer and other sedentary behaviors are associated with being overweight or obese (see and for some recent examples). The strongest evidence is for TV screen time. Apart from being physically inactive while watching TV, TV and snacking go well together, and watching TV also mean being exposed to junk food advertising. Although the evidence for an association between computer screen time and overweight is less consistent, similar arguments are now valid for computer use. Personal computers used intensively for chatting, surfing the internet etc., which also comes with more and more on-screen marketing, and can easily be combined with snacking.
On the other hand, computer-tailored, and web-based personalised health education has been recognised as a promising means to promote healthy lifestyle behaviors (see for a recent open access paper on this topic). With computer-tailoring, respondents get personalised feedback on the behaviour and behavioural determinants and an individualized behaviour change advice. However, such computer-tailored health education may also increase their screen time…

Tuesday, September 18, 2007

Three compulsory physical education lessons per week in schools across Europe?

The Culture and Education Committee of the European Parliament adopted by an overwhelming majority a report by the Hungarian member of parliament Pal Schmitt. This report concluded that physical education should be compulsory in primary and secondary schools and that children should at least have three physical education lessons per week. The report also calls for a better integration between sports and academic subjects in schools.

The recommendations are of great importance given the growing rates of overweight and obesity among European youth. Despite this obesity epidemic, the time allocated to physical education in schools has gone down from an average of 121 minutes per week to 109 since 2002.

The report is scheduled to be put to a plenary vote in November in Strasbourg.

Sunday, September 16, 2007

Obesity prevention: the young and the old

Obesity prevention efforts are mostly aimed at young people. More and more initiatives are trying to encourage ‘ obesopreventive’ behaviours among children and adolescents not only through health education but also, for example, by introducing extra physical education and activity hours in the school curriculum, changing what is for sale in the school canteen, or otherwise trying to make the school a more health behaviour friendly environment (see for some Dutch projects example, The rationale behind a focus on youth is that children’s lifestyle habits may not be as firmly established and may be easier to modify and that overweight in childhood and adolescence is a strong determinant of life-long overweight.
Younger adults are another important target group for obesity prevention. Young adults in the age group of 25-35 or 40 years of age, go through important life course phases that often lead to lower physical activity levels and changes in eating habits. This group is also responsible for razing the next generation and is therefore of utmost importance for obesity prevention among children. The national prevention-of-overweight campaign of the Netherlands Nutrition Center is primarily aimed at this target group (
However, the group with the highest prevalence of overweight and obesity is the elderly. On Thursday professor Marjolein Visser gave her inaugural address as professor of Nutrition and Health and she addressed this issue in a crystal clear manner. Professor Visser is head of the Department of Nutrition and Health ( and her chair is established at the institute of Health Sciences ate the VU University and at the EMGO Institute of the VU University Medical Center (see The evidence she provided showed that Dutch elderly today are much less physically active than a decade ago, and that the prevalence of obesity has doubled in that period among some groups of elderly people (see A study reported by Slingerlandt and others also indicated that Dutch elderly change their physical activity patterns when they retire ( It is clear that obesity prevention should not be restricted to one age group, but deserves a true life course perspective with interventions specifically tailored to the different key age groups.

Tuesday, September 11, 2007

Obesity prevention: From health promotion to health protection.

Friday 7 September the Dutch federation of university medical centers (NFU, see organized a meeting on how to fight the obesity epidemic. After a general introduction on the obesity trends and consequences by professor Jaap Seidel, VU University, Professor Liesbeth Mathus, Amsterdam University Medical Center, gave an overview of medical treatment possibilities, showing that the most promising treatment approach, with long-term follow-up and intensity, is often unavailable in the Netherlands.
Next, the meeting focused on lifestyle interventions to promote prevention of overweight and obesity. Professor Boyd Swinburn from Deakin University, Melbourne (Aus), see, has argued that obesity is a normal reaction to an abnormal environment. This environment that provides opportunities and promotes eating energy dense foods almost anytime, anywhere, and enables avoidance of almost any physical activity, is regarded as the driving force behind the obesity epidemic. Swinburn depicts the obesity epidemic as a ‘runaway weight train’ with the obesogenic environment as the down hill track (see Although most people have freedom of choice where foods and physical activities are concerned, they have to choose in an environment in which unhealthy food choices and lack of physical activity are the easy and intensively marketed choices.
The great accomplishments in public health in countries like the Netherlands, such as the eradication of a number of infectious diseases, improvements in traffic and food safety, and also the reduction in smoking prevalence have all been accomplished by means of an integral approach in which health protection measures, i.e. regulations and environmental change measures, such as building sewage systems, establishing and enforcing traffic laws, or taxing tobacco and creating smoke-free environments, were of key importance. However, despite the environmental causes for the obesity epidemic, obesity prevention efforts are still mostly based on health education and health promotion activities. Such health education is not strong enough to help slow down the weight train. I argued that we need a health protection approach to obesity prevention to finally make a difference. Such a health protection approach should include ‘safe’ food and physical activity environments in, for example, (pre) schools and worksites, a ban on food marketing to children and on unproven direct as well as indirect health claims for foods, and taking ‘protection’ of physical activity into account in all infrastructure projects so that physical activity will again become a necessary and routine part of daily living.

Wednesday, September 5, 2007

European Research Funding for obesity prevention among youth?

Late last week we had our first web-based conference call for the HOPE project (Health promotion through Obesity Prevention in Europe,, to discuss the project’s progress. Colleagues from IOTF (, Erasmus University Medical Centre’s department of Public Health (, University of Oslo’s department of Nutrition (, University of Ghent University’s department of Movement and Sports Sciences (, Unit for Health Services Research and International Health –IRCCS Burlo, in Trieste, Institut National de la Santé et de la Recherche Médicale –INSERM, In Paris, the Karolinska Institute in Stockholm, and from the EMGO-Institute of the VU University Medical Centre ( were all in front of the pc with their headsets to talk about the progress in subsequent workpackages of the EU funded project.

The HOPE project aims to further explore determinants of overweight across Europe, and to identify effective strategies for obesity prevention, based on existing data and networks.
An important extension to the HOPE project would be to use and further enrich this information to develop and test new intervention schemes for prevention of unnecessary weight gain. One of the calls for proposals within the EU 7th framework program (see indeed asks for such research specifically aimed at children and adolescents, and we are now in the final stages of preparing exactly such a proposal together with partners from different countries across Europe. Next week the proposal will need to be in Brussels...

Wednesday, August 22, 2007

Diabetes care and research center in West Friesland

Yesterday I had the pleasure to visit the West-Frisian diabetes research and care center in Hoorn, the Netherlands. This center is a truly unique initiative in which research, innovation and implementation for diabetes prevention and care is realised. This initiative started with the now internationally renowned longitudinal Hoorn study which has to date generated more than 150 scientific publications and still counting (see, and use Hoorn study as your search term to get a nice overview).

In 1989, the Hoorn Study was designed and started to study the prevalence and determinants of type 2 diabetes in the general population in the Netherlands. The Hoorn Study cohort has been monitored ever since and has been extended to include additional study populations. In 1996, to support diabetes care in the region, Professor Giel Nijpels initiated the West-Frisian Care System with a diabetes research centre. Over the years, the number of patients with diabetes who participate in the West-Frisian Care System grew to more than 4000, and the care system encouraged new research. The number of ongoing research projects within the Hoorn Study also grew, and so, in November 2005, a new and larger diabetes research centre opened near Hoorn’s local hospital. The new centre is what I visited: a basic but pleasant building staffed by a very skilled and enthusiastic team, equipped with a vascular laboratory, an ophthalmologic examination unit, storage facilities, and test equipment. A number of researchers presented their studies: clear, well-organised presentations of exciting research related to the determinants, prevention, care and comorbidities of diabetes.

This center strives to realise true integrated diabetes care and to cover the continuum from fundamental research to implementation studies, directly linked to real practice. The Hoorn Study and the West-Frisian Care System’s research activities are part of the EMGO-institute ( of the VU University Medical Center (see and rightly so: it is a very good example of applied research directly linked to improving extramural health care for one of our priorities: diabetes and overweight, its main modifiable determinant.

Sunday, August 19, 2007

Regionally defined healthful diets?

There is no proof beyond reasonable doubt that consumption of ecologically produced foods is more healthful than eating their non-ecological counterparts. Similarly, foods that are produced locally are probably fresher than foods that need to travel over long distances, but there is no convincing evidence that eating such locally produced foods lead to lower disease risk or longer lives.
However, ecological and preferably locally produced foods are to be preferred for environmental protection and sustainability. Protecting the environment is, as professor Johan Mackenbach so clearly describes in a recent paper in International Journal of Epidemiology (see, of great importance for public health. Eating locally may also contribute to the protection of nutritional diversity and local food cultures as argued by the slow food movement (see

So should health promoters start to promote locally produced products as part of their nutrition education efforts to improve population health?
In promotion of healthful eating, basically two different avenues are explored. The first is the nutrients way, with a focus on identification of key nutrients and other food compounds that help to prevent disease and promote health, leading to nutrients specific recommendations and to, for example, use of dietary supplements, nutrient enrichment or fortification of foods, and the development of functional foods. This avenue has been fruitful in the past to help get rid of a number of deficiency diseases in large parts of the world.
However, this nutrient-oriented avenue in general appears to be less effective in addressing the most important present-day nutrition-related health problems that are related to over-consumption rather than deficiencies and stronger related to foods and eating patterns then to nutrients. For example, there is ample evidence that nutrition is directly or indirectly related to CVD, cancer risk and obesity (see for example, there is only very little evidence that specific nutrients contribute to prevention of such conditions.

The second avenue is therefore food and food patterns oriented. This avenue is more closely linked to what people actually eat: foods and meals. Different food guide pyramids, food plates and other nutrition education tools build on this food-oriented avenue (see for example; or

Some attempts have been made to take this food-oriented avenue a few steps further, by describing meal patterns or diets that incorporate the foods for which the strongest evidence has been found for a health enhancing effect such as the famous ‘Mediterranean Diet’(, which is supposed to include olive oil, fruits, vegetables, grains (mostly unrefined), fish, diary in moderate amounts, low quantities of meat and meat products, and a regular but moderate intake of alcohol.

Several of the ingredients of the Mediterranean Diet do not grow well in many areas of the world and other ingredients are not available in large enough quantities to be included in diets across the world. Furthermore, most regions have other culturally and regionally appropriate foods that might be as health enhancing as the ingredients for the Mediterranean diet.

It is a challenge to define such alternative regionally defined diets that may contribute to health promotion and disease prevention, as well as to protection of the environment. Local food production and diversity in food cultures. Together with my Norwegian colleague Dr. Elling Bere of Agder University College, Norway, we have been working on exploring the ‘Nordic Diet’. A paper on our explorations will soon be ready to be submitted for publication! Geit Ost (Norwegian goat cheese) may not be part of such a health enhancing Nordic Diet, but it does taste great!

Friday, August 10, 2007

The EMGO annual report 2006 has been distributed

A few weeks ago the EMGO 2006 annual report (see has been distributed. The publication of this report was a bit later than in earlier years, also because of the change in management of the institute. The annual report gives a comprehensive overview of EMGO's research infrastructure, input in terms of people and budget, and of its output and accomplishments in terms of publications, grants and societal impact. If you want a copy of the annual report, please send an email to

This annual report was the first that I had the pleasure to send out as the new director of EMGO. But since I was only appointed on April 1 2007, I had no responsibility for EMGO's 2006 output and accomplishments. Therefore I can easily brag about EMGO's success in 2006: over 400 international publications, more than 40 doctoral theses, and many millions in grant money obtained. This provides a very good point of departure for establishing EMGO's future (5-10 years) policy in the coming fall. A policy discussion within the EMGO institute has already been launched to establish EMGO's priorities for the years to come. The results of this discussion will be documented in a policy plan that will be discussed on the EMGO 2007 policy day, November 2, 2007.

Thursday, August 9, 2007

ISBNPA 2007 evaluation results

June 21-23 the annual meeting of the International Society of Behavioral Nutrition and Physical Activity (ISBNPA, was held in Olso, Norway. ISBNPA is a research society, so evidently we did some evaluation research to evaluate what the participants thought about the conference program, venue, social events, et cetera. The Executive Committee (EC) of ISBNPA (see the picture of the EC) and the organising committee of the next annual meeting (which will be in Banff, Canada, also see a picture of three members of the local organising committee, chaired by professor Wendy Rogers, the lady in the middle). Information on the Banff ISBNPA 2008 conference can be found at Banff is a fantastic town: in the middle of the Canadian Rockies and easily accessible from Calgary International Airport. The conference will be at a very nice venue (see

As I reported here before, the conference in Olso was well-attended, we had a record high number of over 500 participants. The evaluation indicates that the conference was also generally well-appreciated. 75% of participants found the conference very good to excellent, and only 2.4% found ISBNPA 2007 'poor'. Especially the keynote presentations and symposiums were well appreciated. Most negative remarks were about the food offered during the conference: too few vegetarian options! Good food taking diet-preferences into account is of course of utmost importance at a conference on behavioral nutrition and physical activity, and we will certainly take this into account next year in Banff.

Sunday, July 29, 2007

Gaining weight in social networks

The July 26 issue of the New England Journal of Medicine (see includes a paper by Christakis and Fowler from Harvard Medical School that reports on a social network analysis of the data of the Framingham Study (see The paper shows that people's likelihood to become overweight is much higher when their friends, siblings and/or spouses become overweight. Neighbours' weight changes appeared to have no effects. The study thus suggests that obesity spreads in social networks. Recent reviews of the literature (see for example Ferreira et al. Obesity Reviews 2007;8(2):129-54 [] and Van der Horst et al. Health Education Research2007;22(2):203-26 []) suggest that social environmental factors are important determinants of physical activity and nutrition behaviours. These studies suggest that more and better effort are needed to use social network approaches in obesity prevention. Promising initiatives such as the La Ville Sante (see for a video presentation on this initiative) use a strong community approach with social networking to promote health behaviours in order to help people to prevent unnecessary weight gain.

Thursday, July 19, 2007

Sedentary behaviour or physical activity?

Several studies indicate that people who spend a lot of time on sedentary activities, especially watching TV, are more likley to be overweight. This ralation between sedentary behaviour and weight status appears to be rather independent of the amount of physical activity people engage in. Indeed, people who do a lot of physical activities, may also engange in a lot of sedentary behaviour. Sport activities may make you tired and sit down! A study by Saskia te Velde and others published in BMC Public Health suggest that sedentary behaviours and sport activities cluster among teenage boys (see

But what is a more important risk factor for becoming overweight, lack of physical activity or being sedentary? A recent study published in the International Journal of Behavioral Nutrition and Physical Activity ( shows that 'screen time' (TV, video, computer) at age 15 did predict obesity at age 21, while medium and high intensity physical activity did not. This effect was strongest among girls ( This is one of very few longitudinal studies on this topic, and the results suggest that getting adolescents away from their screens is important for obesity prevention.

Wednesday, July 11, 2007

Culture is in the amniotic fluid…?

At a pre-conference workshop of the 10th European Nutrition Conference in Paris I was one of the speakers on Acquisition of Food-Related Behaviours in Children. The first speaker of the day, Luc Marlier from Strasbourg, France, gave a very interesting and amusing talk on environmental influences on food choice very early in life. He presented his research that clearly indicates that children already obtain food preferences before birth, based on exposure to odours in the amniotic fluid. To which odours the child is exposed before birth is dependent on the eating habits and food choices of the mother. He claimed, therefore, that cultural environmental influences on food choice are already apparent in the womb. During the rest of the day the acquisition of food preferences in children was explored from a genetics perspective, from a social psychology perspective and from a public health perspective, and the important roles of parents, schools and marketing in influencing children’s food choices was highlighted. The different presentations will be made available via the Danone Institute website

Sunday, July 8, 2007

After a succesful ISBNPA conference: physical activity!

The sixth annual meeting of the International Society of Behavioral Nutrition and Physical Activity ended on June 23 with a closing session. Professor Tom Baranowski, the founder and first president of ISBNPA (on the right on the photo; the others are also former presidents of ISBNPA: Gaston Godin and Ron Kleinman), concluded that the conference was a succes with a record-high number of participants and presentations, with high-quality presentations addressing many key issues in behavioral nutrition and physical activity research. Tom Baranowski also stated that upcoming conferences should try to include more presentations on intervention studies, and that the society should continue to try to attract more researchers from countries and regions other that Western Europe, North America and Australia.

After the conference I partcipated in some intensive physical activity myself: a great 13-day bike tour through the westen part of Norway with my partner, Astrid (see how summer-like the higher mountains in Norway are in June). We cycled from Gol to Alesund and back, visiting the Sogne fjell and fjord and many other highlights.

Thursday, June 21, 2007

The sixth ISBNPA conference is ongoing!

Yesterday the sixth annual meeting of the International Society of Behavioral Nutrition and Physical Activity (ISBNPA, see has started in the Folket Huset conference center in Oslo, Norway. After professor Knut Inge Klepp as the chair of the local organising committee and myself as the incoming president of the society gave a brief word of welcome to all the delegates, Dr. Heath McDonald of Deakin University, Australia, gave a very interesting opening keynote on marketing to children. His key message was that a ban on advertising to children may not be a very effective way to help to prevention childhood obesity, since many other way of marketing are in place that are more effective and that will not suffer from advertising bans. After this keynote there was a very pleasant and lively opening reception.
This year’s ISBNPA meeting attracted a record-number of participants, over 500, compared to the 200-350 in earlier years. This is a great accomplishment. ISBNPA is growing into a serious society, also because the ISBNPA journal, the International Journal of Behavioral Nutrition and Physical Activity (see is now officially tracked to establish an official impact factor (the preliminary IF is > 3.0!).
Today the conference is nicely on track with a great keynote by professor Leanne Birch from Pen State University, USA, on parental and early childhood influences on children’s eating behaviors followed by different parallel sessions on behavioural nutrition and physical activity issues.
Many thanks to the local organisers, chaired by professor Knut Inge Klepp and strongly coordinated by Dr. Nanna Lien, for making this possible.

Thursday, June 14, 2007

Diabetes solutions that care

Philips research organised a symposium on diabetes care

On June 14 I attended and presented at a symposium on diabetes care organised by Philips Research on the ‘high tech campus’ in Eindhoven: “Diabetes solutions that care”. The symposium was indeed mostly focussed on diabetes care with presentations on blood glucose monitoring and management, and new antidiabetic drugs. Different speakers expressed that there may be business in diabetes care, more than in prevention. For health insurance companies, for example, there is no incentive to aim at primary prevention of diabetes. However at the start of the day, Wim Wientjes great introductory presentation also addressed the importance of prevention and lifestyle changes. Wientjes was president of the Dutch Diabetes Federation, and is vice president of the International Diabetes Federation. Other presenters came from Germany, UK, and the Netherlands. Mine was the final presentation of the day. A bit strange that the importance of prevention gets most attention at the end… But it was an interesting day, not in the least because of the demonstrations of physical activity monitoring systems Philips is working on and that would be great as an objective basis for tailored health behaviour change feedback.

Sunday, June 10, 2007

Research school CaRe met in Amsterdam

On Friday June 8 researchers from the CaRe research school had their annual retreat. This time the meeting was held in Amsterdam, hosted by the EMGO Institute. CaRe unites researchers from the VU University and Medical Center (EMGO Institute), Maastricht University, Nijmegen University, and the Netherlands Institute for Health Services Research (NIVEL) with an interest in research for trans and extramural health care, primary health care, prevention and health promotion. The theme this year was ‘Prevention Research’.

After Professor Guy Widdershoven, director of CaRe had opened the meeting with a brief overview of CaRe’s mission and goals, I had the honor of chairing the morning session. This morning session was focussed specifically on prevention of mental disorders and on mental health promotion. First Professor Nanne de Vries from Maastricht University build a case for careful planning and evidence-based practice in prevention, and for adopting a broader health promotion perspective in promotion of public mental health. He also illustrated once more the lack of governmental funding for prevention efforts.
Next Professor Pim Cuijpers (In the middle, in the yellow shirt), VU University and EMGO Institute, very clearly illustrated the importance of mental disorders as determinants of population health in the Netherlands. Anxiety disorders and depression are amongst the most prevalent disorders, causing substantial loss of quality of life and are responsible for more than 20% of total health care costs. He further argued that since treatment of mental disorders is certainly not always effective and relapse often occurs, prevention efforts should be intensified.
Heleen Riper (right to Pim in the picture) highlighted one very promising avenue for prevention efforts: web-based prevention programs. The Netherlands is among the countries with the highest internet access rates, and various evidence-based web-delivered programs are available for such disorders as depression, alcohol dependency and anxiety disorders.
Las but not least, our foreign guest, Professor Charles Reynolds (on the mid left, the man in the nice suit) from Pittsburgh University gave his address, in which he presented original research showing the effects of relapse prevention efforts on top of medical interventions for sustaining effects in depression treatment.
A lively round table discussion followed between the four speakers and the approximately 120 CaRe researchers.

Wednesday, June 6, 2007

Health promotion through Obesity Prevention across Europe (HOPE) project kick-off meeting

On June 4 and 5 the steering committee (see picture) of the HOPE project met at the Erasmus University Medical Centre in Rotterdam, the Netherlands. HOPE stands for Health promotion through Obesity Prevention across Europe. More information on the project can be obtained at I am lucky enough to act as the coordinator of this project, assisted by two colleagues from Erasmus University Medical Centre, Willemieke Kroeze and Mauricio Avendano (the two on the right of the front row).

Obesity is one of the main health determinants in terms of burden of disease in Europe, accounting for up to 7% of all healthcare expenditures. It is largely determined by modifiable environmental and life-style factors, which offers a great potential for prevention. The fact that obesity treatment is largely ineffective in the long run, make efforts to prevent unnecessary weight gain even more important. Successful primary prevention could reduce future demands for health care associated with obesity-related chronic conditions such as diabetes, cardiovascular disease and cancer.
In order to design successful primary prevention campaigns, thorough understanding of the behavioural and environmental determinants with a potential for modification is needed. This should take into account the situation in different socio-economic groups

HOPE-project wants to bring all the scientific knowledge on overweight, obesity and their determinants together and use the expertise of researchers all over Europe to help to tackle the obesity epidemic.

HOPE was initiated together with Professor Philip James and Dr. Tim Lobstein of the International Obesity Task Force/International Association of the Study of Obesity (IOTF; ; IASO; HOPE brings together a core group of researchers from the Netherlands, UK, Belgium, Italy, France, Norway, Sweden with an extensive ‘Network of Networks’ with researchers, policy workers and other advocates for evidence-based action towards obesity prevention from across the Europe.

We had a successful steering committee meeting to kick start the project and the actual work is now fully in progress. Please check our HOPE project website regularly!

Thursday, May 31, 2007

Smoke free and obesity

"Engeland goes smoke free" is what was announced on a typical London bus I passed when I walked on Oxford Street towards a World Cancer Research Fund Grant Panel meeting last Tuesday. Following the example of countries like Ireland, Norway and Italy, From July 31, 2007 on, England will ban smoking from all 'enclosed public places' and workplaces, including restaurants. Also in the Netherlands it has been announced that restaurants will have to become smoke free within the near future.

This is very good news for public health: people will be less exposed to second hand smoke. It is also very good news for people who enjoy eating good food in a restaurant unspoiled by a smoky environment.

Within Europe, England has one of the highest rates of overweight and obesity.

This same week the National Statistics Bureau of the Netherlands published their latest findings related to smoking and smoking cessation in the Netherlands (see People in the Netherlands who have stopped smoking are 3.6 K heavier than people who have continued smoking. Never-smokers are a bit heavier than smokers but have a lower mean body weight than ex-smokers.

Earlier research has shown that people who eat out more, have a somewhat higher mean body weight...

Policy measures to discourage smoking are much needed since smoking is still the most improtant determinant of preventable burden of disease. But obesity is a close runner-up. Will measures against smoking further increase obesity rates?

Wednesday, May 30, 2007

A strong closing and a likewise start

Today there was an important double ceremony at the VU University. Professor Houtgast gave his final lecture as professor of Experimental Audiology followed immediately by the inaugural address of Joost Festen as professor of Audiology.

The audiology research is part of the Care & prevention research track of the EMGO Institute (see

Professor Houtgast’s lecture gave a very nice overview of how his field of research emerged and has grown over the thirteen years since he was appointed. The title of his lecture was ‘hearing loss and the beta researcher’ (Slechthorendheid en de Beta-onderzoeker), and during his speech he argued that his field of research involves more than ‘just’ beta expertise. Professor Festen’s lecture was entitled ‘the challenge of understanding’ (Verstaan als Uitdaging) and he gave further evidence that the study of hearing loss is a multidisciplinary research field, involving technical, medical and behavioural expertise. This multidisciplinary environment is exactly what the EMGO institute aims for.

I congratulate professors Houtgast and Festen with their interesting lectures.

Thursday, May 24, 2007

The NHS-NRG project on obesity prevention: promising outcomes, applicable recommendations, but the Dutch government fails to meet its obligations

On May 24 the closing symposium of the Netherlands Heart Foundation NRG (NHS-NRG) project was held. NHS-NRG is a unique multi-stage and multi disciplinary project in which nutritionists, movement scientists, epidemiologists, public and occupational health experts, and behavioural scientists worked together to carefully develop, plan, implement and evaluate different projects for prevention of weight gain.

This NRG project recognised three different primary target groups: adolescents, young adults (20-40 years of age), and recently retired people, since these population groups are at high risk for unnecessary weight gain, are in a phase of the life course where important unhealthy lifestyle changes easily occur, and can be reached at settings that allow intervention activities with a high reach and sustainability, i.e. schools, work places and retirement preparation meetings.

The project included studies to identify specific risk behaviours for unnecessary weight gain, to identify important and modifiable behavioural determinants, and to implement and evaluate the intervention programs.

During this final symposium a summary was given of the most important results and conclusions. Professor Daan Kormhout, the consortium leader for this project, gave a brief overview, followed by an excellent state-of-the-art overview by professor Jaap Seidell. The two postdoc researchers of the NRG project, Drs. Tommy Visscher and Stef Kremers subsequently presented the overview of the results of the project.

The study results confirm the importance of identifying specific obesogenic behaviours and obesogenic environments to develop better targeted intervention programs. The studies also indicate that such well-planned and targeted interventions can initiate and help to sustain important changes in obesogenic behaviours and/or indicators of overweight and obesity.

Based on the project’s results recommendations for overweight prevention programs were provided. In summary, these recommendations state that prevention for overweight should focus on specific energy-balance related behaviours, should include strategies to improve motivation, abilities and environmental opportunities, and should be combined with long-term monitoring to further study the effects and learn for future initiatives. These recommendations are in line with earlier statements, but are now based on better evidence.

In the second part of the symposium, representatives of four organisations responsible for policy and implementation related to prevention of overweight (the Netherlands ministry of Health, the Netherlands Nutrition Foundation, the Netherlands Organisation for Promotion of Physical Activity, and the Netherlands Heart Foundation gave their reactions to the recommendations presented. These reactions were discussed with the audience of scientists, policy makers, and public health professionals.

The NRG recommendations were well received among the three implementation organisations. However, more negative news was heard from the representative of the Ministry of Health. She stated that the budget for prevention in general and obesity prevention in particular will most probably be further cut, and that collaboration with other ministries with important tasks related to providing opportunities for an energy-balanced lifestyle (e.g. Infrastructure, Food and Agriculture) was hindered by lack of willingness to seriously collaborate. This despite the fact that obesity rates in the Netherlands still grow to further unacceptable levels in all age groups and social classes, and despite the fact that the Dutch government has signed the European Charter for counteracting obesity. Signing this charter obligates countries to intensify their activities to prevent obesity (

Tuesday, May 22, 2007

The impact of computer-tailored health education

Recently some new and exciting papers on the impact of computer-tailored health education were published. Computer-tailored health education is a way to use ICT to mimic personal health behaviour counselling. Computer-tailoring programs use (electronic) questionnaires to assess respondents' health behaviours and behavioural determinants and provide tailored, personalised and individualised feedback and advice. Computer-tailoring was originally applied with paper-and-pen questionnaires and print feedback, and a systematic review of the literature clearly indicates that this form of health education is superior to more traditional, generic forms of health education (see Kroeze, Werkman & Brug, Ann Beh Med 2007;31:205-223). More recently studies have been conducted and reported that applied web-based tailoring (see for example Brug et al. Eur J Clin Nutr 2005;59:S130-S137) and applied computer-tailoring among various target populations, such as children and adolesents. Leen Haerens of Ghent University recently published one of the first papers to test school-based computer-tailored nutrition education among adolescents. Her study published in Public Health Nutrition (2007;10:443-449) indicates that computer-tailored education alone is not enough.

Corneel Vandelanotte published a paper in Annals of Behavioral Medicine (2007;33:213-219) that for the first time reports a study on the longer-term (2 year follow-up) of his diet and physical activity computer-tailored intervention. His study indicates that effects of computer-tailoring can be sustained. (see for a Dutch example of a web-based computer-tailored life style intervention for diabetes prevention).

Sunday, May 13, 2007

Should we promote fruits and vegetables?

In yesterday’s edition of ‘De Volkskrant’, a leading national newspaper in the Netherlands, professor Martijn Katan posited that fruit is an overrated icon of healthful nutrition (see for the article with additional background information). Martijn Katan is professor of nutrition at the Institute of Health Sciences of the VU University Amsterdam.

Katan describes how fruit came to be one of the foods to be promoted by nutrition educators: based on observational studies preliminary evidence indicated that high intakes of fruit contributed to cancer prevention. However, more recent more robust studies indicate that the inverse association between fruit intake and cancer risk is much weaker than the initial studies suggested. Furthermore, Katan describes that fruit juice may contribute to tooth decay and overweight among youth similarly as soft drinks may do: fruit juice contains similar amounts of sugar and has a similarly low PH value.

Fruit and vegetable may on the other hand contribute to obesity prevention because fruits and vegetables have a lower energy density than many other foods. If children eat fruit and vegetables instead of chocolate bars, cookies, savoury snacks and other ‘junk foods’, fruit and vegetable intake may lead to lower energy intake, but there is not yet convincing evidence available to support this.

Nevertheless, most nutrition authorities across Europe think that the evidence for the health promoting properties of fruits and vegetables is still strong enough to include fruits and vegetables promotion in their official dietary recommendations. Later this year the World Cancer Research Fund will publish their new comprehensive report on nutrition and cancer risk, which will include the latest reviews of the scientific literature on fruits, vegetables and cancer risk.

For information on a cross-European project to promote fruits and vegetables among schoolchildren: see

Friday, May 11, 2007

Exploration of economic measures to promote healthful eating

A recent paper in the International Journal of Behavioral Nutrition and Physical Activity explores important 'economic environment' intervention possibilities to promote healthful dietary habits. This approach is much debated, and this paper sheds some empirical light on the issue. The paper is 'open access' and can be found at ; see for more intresting papers.
This paper by Danish researchers Jensen and Smed addresses the potential for using economic regulation, e.g. taxes or subsidies, as instruments to combat the increasing problems of inappropriate diets, leading to health problems such as obesity, diabetes 2, cardiovascular diseases etc. in most countries. Such policy measures may be considered as alternatives or supplements to other regulation instruments, including information campaigns, bans or enhancement of technological solutions to the problems of obesity or related diseases. 7 different food tax and subsidy instruments or combinations of instruments are analysed quantitatively. The analyses demonstrate that the average cost-effectiveness with regard to changing the intake of selected nutritional variables can be improved by 10–30 per cent if taxes/subsidies are targeted against these nutrients, compared with targeting selected food categories. Finally, the paper raises a range of issues, which need to be investigated further, before firm conclusions about the suitability of economic instruments in nutrition policy can be drawn.