Saturday, December 28, 2013

Exploring nationwide dissemination of a Dutch school-based obesity prevention program

The evidence-based Dutch Obesity Intervention in Teenagers (DOiT) program is a school-based
obesity prevention program for 12 to 14-year olds attending the first two years of prevocational education. In a paper just published in the journal BMC Public Health, with Femke van Nassau as first author we describe a study  to evaluate (a) the nationwide dissemination process of DOiT in theNetherlands, and (b) the relationship between quality of implementation and effectiveness during nationwide
dissemination of the program in the Netherlands.

Friday, December 6, 2013

DEDIPAC has officially started

To address the major societal challenges and enhance cooperation in research across Europe, the European Commission has initiated and facilitated ‘joint programming’. The Determinants of Diet and Physical Activity (DEDIPAC) Knowledge Hub (KH) is the first action of the European Joint Programming Initiative (JPI) ‘A Healthy Diet for a Healthy Life’. The objective of DEDIPAC is to contribute to improving the understanding of determinants dietary, physical activity and sedentary behaviours. DEDIPAC KH is a multi-disciplinary consortium of scientists from 46 research centers supported by joint programming grants from 12 countries across Europe. In the initial three years DEDIPAC KH will develop, exchange, harmonize and share expertise, methods, measures, data and other infrastructure to enable a broad multidisciplinary approach, including biological, ecological, psychological, sociological, and economic determinants and their interrelationships.
Today we had the kick off of DEDIPAC at the EMGO Institute for Health and Care Research of the VU University Medical Center, where the DEDIPAC core team met to prepare for the work to be conducted in the coming weeks, months and years.

Wednesday, November 27, 2013

Family factors, breakfast habits and children's weight status across Europe

In a paper just published in the journal PLOS ONE we report on an investigation of associations of family-related factors with children’s breakfast consumption and body mass index (BMI-z-score). We also examined if children’s breakfast consumption mediates associations between family-related factors and children’s BMI. Our paper was part of our reports on the cross European ENERGY study, and Dr. Wendy van Lippevelde of Ghent University was first author on this paper.
Data from more than 6000 10-12 year olds and from one of their parents from 12 countries were used for this study.

We found that family breakfast was inversely associated with children's BMI: children where family breakfast was more common, had lower body weights for their heights. A broad range of family and parenting variables were associated with breakfast habits, such as parental encouragement, paying attention, permissiveness, and parental self-efficacy to address children’s nagging. The results support  that parenting factors should be addressed to promote healthy breakfast habits, which
may contribute to better energy balance in school-age children.

Sunday, November 17, 2013

Active gaming: prevalence and correlates in Dutch adolescents

Active gaming, i.e. playing computer games that require physical activity instead of sitting, is regarded as a possible effective strategy to promote physical activity and discourage too much sitting. In a study just published online in the Journal of Science and Medicine in Sports -with Monique Simons as first author- we studied the prevalence and identified demographic correlates of active and non-active gaming among adolescents.
In a among 373 12-16 year olds we asked the respondents about their game behavior and a range of background characteristics.
Of all respondents, 3% reported to play exclusively active games, 40% active games and non-active games, 40% exclusively non-active games, and 17% not playing video games at all. Active gaming adolescents played active games on average on 1.5 days per school week for 36  minutes and 1 day per weekend for 42 minutes. Non-active gamers played quite a bit more; on average on 3.3 days per school week for 65 minutes and 1.4 days per weekend for 80 minutes. Adolescents attending lower levels of education were more likely to play active games ≥1 hour per week than adolescents attending higher educational levels. Boys and older adolescents were more likely to play non-active games >7 hours per week, than girls or younger adolescents.
We concluded that many adolescents play active games, especially those following a lower educational level, but time spent in this activity is relatively low compared to non-active gaming. To be feasible as a public health strategy, active gaming interventions should achieve more time is spent on active gaming at the expense of non-active gaming.

Wednesday, November 6, 2013

Genetic and environmental factors in adolescent sleep duration

In a study just published on-line in the journal Twin Research and Human Genetics -with Dr. Saskia te Velde as first author- we assessed to what extent lack is associated with genetic and environmental factors.  Lack of sleep is associated with physical and mental health. Lack of sleep is an important predictor of overweight, and as we published in an earlier study: many children across Europe sleep fewer than 8-9 hours and their sleep duration is associated with overweight and obesity. A twin-family design was used to gain insight into the genetic and environmental contributions to variation in sleep duration; data came for the Netherlands Twin Registry. The study sample consisted of 6,319 adolescent twins and 1,359 non-twin siblings, aged 12 to 20 years  Results showed that the prevalence of shorter than optimum sleep duration, that is, less than 8 hours per night, was high, with the highest prevalence rates in later adolescence. The contribution of genetic and environmental factors to individual differences in sleep duration was dependent on age. Variation in sleep duration at the age of 12 years was accounted for by genetic (boys: 34%, girls: 36%), shared environmental (boys: 28%, girls: 45%), and non-shared environmental factors (boys: 38%, girls: 19%). At the age of 20 years, the role of genetic (boys: 47%, girls: 33%) and non-shared environmental factors (boys: 53%, girls: 67%) was more pronounced. It can be concluded from the results that individual differences in sleep duration were accounted for by genetic and non-shared environmental factors throughout adolescence, whereas shared environmental factors account for a substantial part of variation during early adolescence only.

Monday, October 28, 2013

Remote sensing to define environmental characteristics related to physical activity and diet

In a paper just published online in the journal Health & Place, with Dr. Charriere from the Nutritional Epidemiology Research Unit of Université Paris as first author, we report on a systematic literature review on the use of free geospatial services as potential tools to assess built environmental characteristics related to dietary behaviour and physical activity.  This review was conducted as part of the SPOTLIGHT (Sustainable prevention of obesity through integrated strategies) project Thirteen  studies were included conducted in urban contexts, with Google Earth and Google Street View as the two main free geospatial services used. The agreement between virtual and field audit was higher for items related to objectively verifiable measures such as the presence of physical activity infrastructure and equipment, and lower for subjectively assessed items such as aesthetics, street atmosphere, et cetera. Free geospatial services appear as promising alternatives to field audit for assessment of objective dimensions of the built environment.

Saturday, October 19, 2013

Another paper on mediators of effect of exercise interventions among cancer survivors

Earlier this week I reported on a paper that was published in the journal Cancer on research to shed light on mediators of exercise interventions among cancer survivors. Information on mediators helps us to better learn how and why exercise interventions may help cancer survivors to gain better health and quality of life. That study looked at mediators of the resistance and aerobic exercise intervention effect on physical and general health in men undergoing androgen deprivation therapy for prostate cancer. Now, in the same week another paper was published, this one in the journal Psycho-Oncology, looking again at mediators of an exercise intervention. This study analyzed data from 209 cancer survivors -more than half breast cancer - to explore significant mediators of effects of exercise on quality of life.
The results showed that the beneficial effect of group-based physical exercise on quality of life of the cancer survivors was mediated by increased physical activity, general self-efficacy and mastery, and subsequent reductions in fatigue and distress. These results indicate that in addition to physical activity, future interventions should target self-efficacy and mastery. This may lead to reduced distress and fatigue, and consequently improved quality of of cancer survivors.

Wednesday, October 16, 2013

Mediators of exercise intervention effects among cancer patients

In order to better learn how and why exercise interventions may help cancer survivors to gain better health and quality of life, we need more insight in the so-called mediators of the effects of exercise interventions for cancer survivors. The POLARIS study-that I reported here on before- was especially designed for this purpose.
This week an earlier explorative study to shed light on mediators of exercise interventions among cancer survivors was published in the journal Cancer. This study looked at mediators of the resistance and aerobic exercise intervention effect on physical and general health in men undergoing androgen deprivation therapy for prostate cancer.
The exercise intervention was found to significantly improve physical and general health. Upper body muscle strength and walking speed significantly mediated the intervention effect on physical health  accounting for 53% of the total effect. Walking speed and fatigue were found to be mediators of the effect on general health, accounting for 51% of the total effect.

Sunday, September 22, 2013

Prevalence of depression in cancer patients

In a meta-analysis study just published on-line in Psycho-Oncology, we aimed to investigate the prevalence of depression in cancer patients assessed by diagnostic interviews and self-report instruments, and to study differences in prevalence between type of instrument, type of cancer and treatment phase.
Depending on the way depression was measured in the different studies, the  prevalence of depression ranged from 8 to 17%, and from 3% in patients with lung cancer to 31% in patients with cancer of the digestive tract. Prevalence of depression was highest during treatment, but 8-15% prevalence of depression was still found one year or longer after diagnosis.

Tuesday, September 17, 2013

Predicting OptimaL cAncer RehabIlitation and Supportive care (POLARIS)

We just published in the journal Systematic Reviews -with Dr. Laurien Buffart as first author- the rationale and design for meta-analyses of individual patient data of randomized controlled trials that evaluate the effect of physical activity and psychosocial interventions on health-related quality of life in cancer survivors, i.e. the POLARIS study.
Because of better cancer treatments, we have more and more cancer http://www.polaris-study.orgsurvivors. Effective interventions to improve quality of life of these cancer survivors are essential. Numerous randomized controlled trials have evaluated the effects of physical activity or psychosocial interventions on health-related quality of life of cancer survivors, with generally small sample sizes and modest effects. Better targeted interventions may result in larger effects. To realize such targeted interventions, we must determine which interventions that are presently available work for which patients, and what the underlying working mechanisms are. Individual patient data meta-analysis has been described as the 'gold standard' of systematic review methodology. Instead of extracting aggregate data from study reports or from authors, the original research data are sought directly from the investigators. Individual patient data meta-analyses allow for adequate statistical analysis of intervention effects and moderators of such effects. In the paper we just published, we report the rationale and design of the Predicting OptimaL cAncer RehabIlitation and Supportive care (POLARIS) Consortium. The primary aim of POLARIS is 1) to conduct meta-analyses based on individual patient data to evaluate the effect of physical activity and psychosocial interventions on the health-related quality of life of cancer survivors; 2) to identify important demographic, clinical, personal, or intervention-related moderators of the effect; and 3) to build and validate clinical prediction models identifying the most relevant predictors of intervention success.

Who is more likely to smoke during pregnancy in the Netherlands?

Smoking during pregnancy is a risk factor for various adverse birth outcomes. In order to develop and target interventions to reduce smoking during pregnancy, insight is needed into the characteristics associated with pregnant women who smoke. In a study we just published in PLOS ONE with Ruth Baron as first author we looked at associations of thirteen socio-demographic or lifestyle-related characteristics with ‘any smoking’, ‘daily smoking’ and ‘occasional smoking’ during pregnancy. Our study sample was drawn from the DELIVER study, a cohort of 6107 pregnant women in primary care in the Netherlands who were up to 34 weeks pregnant. Characteristics most strongly associated with any smoking were low education, being of Turkish ethnicity and having no partner. Women of Dutch ethnicity were three times more likely to smoke than those from Dutch-speaking Caribbean countries and non-religious women were much more likely to smoke than religious women. Daily smokers were more likely to be associated with other unfavorable lifestyle-related characteristics, such as not taking folic acid, being underweight, and having had an unplanned pregnancy. There is still much potential for health gain with respect to smoking during pregnancy in the Netherlands. Daily and occasional smokers appear to differ in characteristics, and therefore possibly require different interventions.

Friday, August 30, 2013

Prof. Guus van Dongen writes about VUmc and the knowledge based economy

The Randstad region website presents a column by VU University medical center's professor Guus van Dongen, who build a case for a 'knowledge-based economy" and how our medical imaging center serves as an example. Please click here.

Tuesday, August 20, 2013

Can ethnic differences in children’s body composition be explained by differences in eating, physical activity, sedentary or sleeping?

In earlier research published in the journal Pediatric Obesity, we have found that -across Europe and in other affluent countries- children from non-native ethnicity are in general more likely to be overweight or obese, and to have unhealthy eating , physical activity and sleeping patterns than 'native' children. In further analyses just published in the journal PLOS One, with Juan Miguel Fernández-Alvira as first author, we explored if differences in eating, physical activity, sedentary and/or sleeping behaviors according to ethnic background can explain the ethnic differences in overweight and obesity. We conducted mediation analyses on the data of the ENERGY cross sectional study, a cross-European study among 10-12 year old schoolchildren and their parents across eight countries in Europe. For this study we used only data from the countries where ethnic differences in overweight and obesity were most prominent: Greece and the Netherlands. In these two country the ethnic differences were, however, in the opposite direction. As we published before in PLOS One, in Greece -the country with the highest prevalence of childhood overweight and obesity-, children from ethnic minorities are less likely to be overweight or obese than native Greek children. In the Netherlands -a country with relatively low prevalence of overweight and obesity-, ethnic minority children are more likely to be overweight or obese than native Dutch children. In the now published paper in the same journal, we show ethnic differences in children’s body composition were partially mediated by differences in breakfast skipping in the Netherlands and sugared drinks intake, sports participation and sleep duration in Greece.

Sunday, August 18, 2013

Children's physical activity and sedentary time, home and neighborhood environments in urban and rural areas.

The environments children live in, their home as well as their school and neighborhood environments, are likely to influence what they do and do not do. A library of research now suggests that such environments influence children's physical activities and sedentary behaviors. How -via what kind of causal pathways- such influences come about, is, however, certainly not well researched and thus not clear. In a study just published online in the scientific journal Health and Place, first authored by Prof. Jo Salmon, Deakin University, Melbourne, we studied associations of home and neighbourhood READI) study, i.e. a cohort of women (aged 18–45 years) and their children (5–12 years). 613 children and their mothers participated. Urban children had higher screen time (i.e. TV and computer time) than rural children. In rural areas access to physical activity equipment in the home was higher, and mothers set better examples for their children regarding PA, had better knowledge of the neighborhood, a stronger social network, and reported higher safety than urban mothers.  Among urban children, the importance of doing PA together as a family was positively associated with ST. Interventions targeting PA and ST may need to target different factors according to urban/rural location.
environments with children's physical activity (PA), and sedentary time (ST). We also investigated if such associations were different for children living in urban vs. rural locations. Data were from the the Resilience for Eating and Activity Despite Inequality (

Wednesday, August 14, 2013

Obesity rates among pre-schoolers from low income families are declining in many states in the US

A 'vital signs'  report published by the US Centers of Disease Control and Prevention, published August 9, shows that in 18 out of 43 states or territories in the US obesity rates among 2-4 year olds from low income families, have declined significantly between 2008 and 2011. No change was observed in 20 states, while 3 states showed increased obesity rates. The results are based on measured height and weight from 11.6 million low-income children. In USA today, US experts say that the changes are small, but encouraging, because this is the first time in a generation that trends appear to be moving in the right direction.

Wednesday, July 24, 2013

Evidence-based physical activity guidelines for cancer survivors

Physical activity during and after cancer treatment has beneficial effects on a number of physical and psychosocial outcomes. In a paper that was just published in the journal Cancer Treatment Reviews, with Dr. Laurien Buffart as first author, we discuss the existing physical activity guidelines for cancer survivors and describe future research directions to optimize prescriptions for physical activity among cancer survivors.
Physical activity guidelines for cancer survivors suggest that physical activity should be an integral and continuous part of care for all cancer survivors. However, the development of these guidelines has been limited by the research conducted. To be able to develop more specific guidelines, future studies should focus on identifying clinical, personal, physical, psychosocial, and intervention moderators explaining ‘for whom’ or ‘under what circumstances’ interventions work. Further, more insight into the working mechanisms of exercise interventions on health outcomes in cancer survivors is needed to improve the efficacy and efficiency of interventions. Finally, existing programs should embrace interests and preferences of patients to facilitate optimal uptake of interventions. In conclusion, current physical activity guidelines for cancer survivors are generic, and research is needed to develop more personalized physical activity guidelines. In an ongoing project called POLARIS (Predicting OptimaL cAncer RehabIlitation and Supportive care) we are using existing data from many countries in individual patient data meta analyses to inform better tailored and targeted recommendations for cancer survivors.

Friday, June 28, 2013

Which health behaviors are associated with socio-economic status differences in overweight in school children?

It is well known that the prevalence of overweight and obesity is considerably higher among youth from lower socio-economic families, but there is little information about which eating and physical activity behaviors may play a role in explaining these differences in overweight. In a paper just published in the International Journal of Behavioral Nutrition and Physical Activity, with Juan Fernandez Alvira as first author, we looked at which behavior mediate the association between parental education and children's body composition. Data were obtained from the cross sectional study of the "EuropeaN Energy balance Research to prevent excessive weight Gain among Youth" (ENERGY) project and we explored the possible mediating effect of sugared drinks intake, breakfast consumption, active transportation to school, sports participation, TV viewing, computer use and sleep duration.
The association between parental education and children's b
ody composition was partially mediated by breakfast consumption, sports participation, TV viewing and computer use.

Thursday, June 27, 2013

Interventions in low SES neighborhoods to promote health behavior: implementation issues

Although many interventions aiming to improve social and physical environments in low socio-economic status neighborhoods have been and are being implemented, what enhances and what promotes implementation of such interventions has rarely been studied. In a paper just published in the European Journal of Public Health, with Dr. Jeroen Lakerveld as first author, we assessed 18 implemented interventions in three underprivileged neighborhoods. Health promotion experts and representatives from the neighborhoods scored each of the interventions on 'RE-AIM', i.e. on reach, efficacy, adoption, implementation and maintenance of the interventions.
Effectiveness and implementation success were higher when the target group was involved in the planning of the intervention. Interventions were better maintained in the absence of competition with other projects. If the intervention was informed by a thorough inventory of  the current situation the effectiveness, adoption and implementation were better.  Involvement of the target group during implementation resulted in higher reach, effectiveness and adoption. Finally, the reach was higher when the intervention was supported by manpower.

Tuesday, May 28, 2013

Schoolchildren across Europe sit about 65% of their school hours.

In a study just published in the Journal of Science and Medicine in Sport, with Dr. Maartje van Stralen as first author, we investigated how much time children spent on sedentary and physical activities at school in five European countries. We also looked at differences between countries and differences between girls and boys, children from native and foreign ethnicity, normal and overweight children, and from lower or higher educated parents.
We used data from the ENERGY cross-European cross-sectional survey. Primary schoolchildren (n=1025) aged 10-12 years in Belgium, Greece, Hungary, the Netherlands, and Switzerland wore accelerometers -a device to objectively measure (lack of) activity- for at least six consecutive days. Only weekdays were used for this study to calculate the percentages of school-time spent in sedentary activities and moderate to vigorous intensity physical activities. Children were also measured for their height and weight.
We found that across the five countries, the children spent on average 65% of their time at school in sedentary activities and 5% on moderate to vigorous intensity activities. The differences between countries were small. Girls spent somewhat more time sitting than boys (67 vs. 63% of their school hours) and a little less time on moderate to vigorous intensity activities (4 vs. 5%). Children who were overweight were substantially  less active than normal weight children, but we found no differences according to parental education or ethnicity.

Friday, May 24, 2013

Joint programming initiative a healthy diet for a healthy life: DEDIPAC proposal getting close to completion

Led by the management team of the DEDIPAC (determinants of diet and physical activity) Knowledge Hub of the Joint Programming Initiative 'A Healthy Diet for a Healthy Life' , the DEDIPAC consortium is now in the final weeks of completing their proposal for strengthening research and building the research infrastructure for cross European research on determinants of diet and physical activity. The DEDIPAC MT had another live meeting last week at VU University Medical Center in Amsterdam to prepare the next draft of the DEDIPAC knowledge hub proposal, which is now circulated for final comments and adjustments among the consortium members.

DEDIPAC KH is a network of selected research groups and scientists from 12 JPI Member States that will carry out a programme of joint trans- und multidisciplinary activities for a better understanding on how individual, social and environmental determinants influence food and physical activity choices, and primarily to build a good network an infrastructure for such research.

DEDIPAC has three thematic areas: data assessment and harmonization. analyses of determinants, and interventions and policies. The proposal will be submitted in about two weeks time, and will be externally reviewed in July.

Sunday, May 19, 2013

Eating while watching TV, and weight status in schoolchildren across Europe

In the ENERGY study data set, we have explored if and how eating while watching TV is associated with weight status among 10-12 year old children in 8 countries across Europe. The results have just been published in the International Journal of Behavioral Nutrition and Physical Activity, with Froydis Vik as first author. Many studies in recent years have reported on the association between so-called sedentary behavior and weight status, and it has been suggested that children who sit more, have higher likelihood to be overweight and obese, and metabolic ill health. However, a recent review of the literature published in Obesity Reviews as well as a further recent original study published in Plos ONE failed to show that such sedentary behaviors predict metabolic ill health. However, for one specific sedentary activity, i.e. TV watching, the associations with overweight and obesity appear to be stronger. It has been suggested that 'mindless'  eating while watching TV could be an underlying factor.
In an earlier study, published in Public Health Nutrition, we already looked at having breakfast while watching TV, breakfast skipping and overweigh/obesity. In the present study we looked at all three meals -breakfast, lunch, dinner, and indeed found that children who watched TV while eating their main meals, especially while having lunch or dinner, had somewhat (20-30%) higher odds to be overweight or obese. Our study also further provided supportive evidence that children who eat regular meal -i.e. who do not skip breakfast or dinner-s are less likely to be overweight or obese.

Tuesday, May 14, 2013

No strong evidence that effectiveness of Dutch behavioral nutrition and physical activity interventions differ according to socio-economic status

Reducing health inequalities is a policy priority in many countries. Socio-economic status (SES) differences in obesity and its underlying health behaviors, i.e. diet, physical activity and sedentary behaviors, are among such important health inequalities in many affluent as well as developing countries. Although such inequalities have been well-documented, we are still largely in the dark when it comes to how we can reduce such inequalities. One way to shed some more light on this issue is to  investigate differential effectiveness of interventions aimed at obesity
prevention, the promotion of physical activity or a healthy diet by SES, i.e. to study is such interventions work for different SES groups.
In a paper just published in the American Journal of Preventive Medicine, first authored by Tessa Magnee and led by Frank van Lenthe, 26 Dutch studies conducted since 1990 were re-analysed for this purpose.  Seven of these lifestyle interventions were rated more effective and four less effective in groups with high SES; for 15 studies no differential effects could be demonstrated. If we looked at the specific settings and strategies of these interventions the following pattern appeared: the one study conducted in the healthcare setting showed comparable effects in both socioeconomic groups. The only mass media campaign provided modest evidence for higher effectiveness among those with high SES. Individually tailored and workplace interventions were either more effective in higher-SES groups or no differential effects were demonstrated. School-based studies showed mixed results. Two of six community studies provided evidence for better effectiveness in lower-SES groups; none were more effective in higher-SES groups. One high-intensity community-based study provided best evidence for higher effectiveness in low-SES groups.
We concluded that for the majority of interventions aimed at obesity prevention, no strong systematic differences in effects could be established. Interventions may widen as well as reduce socioeconomic inequalities in these outcomes. 

Thursday, April 11, 2013

A joint programming initiative to study determinants of diet and physical activity across Europe: DEDIPAC

Yesterday and today 30+ scientists from 7 countries in Europe met as the main writing team to prepare a proposal for the first pilot of the Joint Programming Initiative (JPI) 'A healthy diet for a healthy life'. This JPI's vision is to ensure that all consumers across Europe have the motivation, ability and opportunity to eat a healthy diet and be physically active.
The JPI has three main pillars:
1. Determinants of diet and physical activity
2. Diet and food production
3. Diet-related chronic disease
The Knowledge Hub on the DEterminants of DIet and Physical Activity. In the framework of DEDIPAC, a network of selected research groups and scientists from 12 JPI Member States will carry out a programme of joint trans- und multidisciplinary activities for a better understanding on how individual, social and environmental determinants influence food and physical activity choices. A few weeks ago, I was elected coordinator of this DEDIPAC knowledge hub. DEDIPAC has three thematic areas:

Thematic Area A: Data Assessment and Harmonization, led by Prof. Pieter van t Veer, Wageningen University and Research Center
Thematic Area B: Analysis of Determinants, led by Prof. Nanna Lien, University of Oslo
Thematic Area C: Interventions and Policies, led by Prof. Ilse de Bourdeaudhuij, University of Ghent
In the last two days these thematic areas were specified in work packages, tasks and deliverables to be strived for in the next few years to build a better research and monitoring infrastructure for such determinant research across Europe.

Wednesday, March 27, 2013

Physical activity and the risk of developing lung cancer among smokers: A meta-analysis

In order to investigate the relationship between physical activity and lung cancer among smokers and whether this relationship differed according to physical activity intensity, smoking status, and gender, we conducted a meta analysis. The paper reporting on this study was just published in the Journal of Science and Medicine in Sport. Dr. Laurien Buffart is the first author of this publication.
Pooled analysis of the results of 7 cohort studies showed that physical activity was associated with a somewhat reduced risk of lung cancer in smokers. We did not find clear dose–response relationship regarding exercise or smoking intensity, i.e. high levels of physical activity did not show a higher risk reduction than moderate physical activity levels, and the association between physical activity and risk reduction did not differ between heavy and light smokers.
Results of this meta-analysis thus indicate that leisure time physical activity is associated with reduced risk of developing lung cancer among smokers. But, of course, non smoking is much more important and effective in preventing lung cancer .

Tuesday, March 26, 2013

An Amsterdam University Medical alliance

Today the two university medical centers in the Amsterdam region, VU University Medical Center, and the Amsterdam Medical center of the University of Amsterdam signed an alliance agreement. NRC Handelsblad -one of the Dutch national newspapers- covered this important development in today's paper and their website. The two centers will join forces to face the grand challenges for health care and biomedical research and education. Regarding scientific research, the two centers will develop joined translational research focus areas, organized in joined research institutes, based on their existing excellence in oncology, neurosciences, cardiovascular disease, infectious diseases and immunology, gastro-intestinal and metabolic disease, and public health and movement sciences. With this concentration in expertise, we will be able to further improve our international positions in these important research areas and contribute even more significantly to improving health care, prevention and rehabilitation.

Longer sleep means slimmer kids?

More and more research indicates that sufficient sleep helps to prevent overweight and obesity. Lack of sleep may lead to hormonal disturbances related to increased likelihood to gain unnecessary weight and become overweight, and lack of sleep may also be associated with lower physical activity and exercise levels or my lead to overeating. In our ENERGY study data we have now also explored the association between sleep habits and weight status in 10-12 year old schoolchildren across 7 countries in Europe. Few studies have differentiated between weekday and weekend day sleep duration in their association with indicators of weight status in children. Therefore, we examined the association of week and weekend day sleep duration with indicators of body composition, i.e. measured body mass index (BMI) and waist circumference (WC). The paper presenting the results of these analyses is now published in the journal PLOS One. In our analyses we adjusted for other behaviors that have been found te be associated with overweight/obesity (dietary, physical; activity and sedentary behaviors). Our results confirmed earlier findings that kids who sleep have lower BMIs and WCs. The association with weekday sleep were stronger than for weekend sleep.

Saturday, March 23, 2013

B.Slim: Healthy eating and physical activity with the DOiT program; the Wellantcollege in Amsterdam example

The DOiT (Dutch Obesity intervention in Teenagers) is an evidence-based program to encourage teenagers to adopt and maintain healthier eating and physical activity to contribute to prevention of overweight and obesity. The program was developed and evaluated by a team led by Dr. Amika Singh. The program has been adopted by the municipality health service in the Amsterdam region, and is implemented in secondary schools here.  The further dessemination an implementation is evaluated by Femke van Nassau. A video about this implementation -with one school as an example- was shot by the Amsterdam municipality health service and broadcasted on YouTube.

Thursday, March 14, 2013

Breakfast skipping, watching TV while eating breakfast, and underweight, overweight and obesity in school children across Europe

In a paper just published in e-pub in the journal Public Health Nutrition we describe a study looking at the relationships between skipping breakfast, watching TV while having breakfast, and weight status in 10-12 y old schoolchildren in eight countries across Europe. This paper is another product from the cross-European ENERGY study.

We found that, as compared to children who eat breakfast every day without watching TV (and  adjusting for sex, ethnicity and parental level of education) children who skip breakfast at least once a week were 1.2 times more likely to be overweight and 1.8 times more likely to be obese; children who watch TV while having breakfast were half as likely to be underweight and 1.4 times more likely to be obese than kids who do not watch TV while having breakfast. Our results are thus in line with earlier studies that also indicated that breakfast skippers are significantly more likely to be overweight and obese. Our study further indicates that watching TV while having breakfast is associated  with higher risk for obesity, but also with lower risk for underweight in schoolchildren.

Thursday, February 28, 2013

Effects of exercise in patients treated with stem cell transplantation for a hematologic malignancy

In a paper just published on-line in the journal Cancer Treatment Reviews, we reported a systematic review and meta-analysis of studies looking into  the effectiveness of exercise interventions in patients with hematologic malignancies treated with stem cell transplantation. We included randomized controlled trials comparing exercise with usual care, in which at least 75% of the patients had a hematologic malignancy. based on th eights studies that we were able to review, the results showed that xercise had a statistically significant  effect on cardiorespiratory fitness,  muscle strength, lower fatigue, quality of life, and physical, emotional and cognitive functioning. In conclusion, exercise seems to have beneficial effects in patients treated with stem cell transplantation. The review was led by Saskia Persoon, one of the PhD students contributing to the Alpe D'Huzes Cancer Rehabilitation Program (A-CaRe).

Sunday, February 24, 2013

What do 200 kCal look like on your plate?

'FROOT', "your daily dosis of web vitamins" published a very nice series of pictures of 200 kCal of different foods on a same-size plate.

Wednesday, February 6, 2013

Parental support is important for children's participation in sport activities across Europe

Sport participation makes an important contribution to children's overall physical activity. Understanding influences on sports participation is important and the family environment is considered key, however few studies have explored the mechanisms by which the family environment, parents in particular, influences children's sport participation. The purpose of our study just published in the International Journal of Behavioral Nutrition and Physical Activity, was to explore associations between factors in the family environment with schoolchildren's sports participation. Additionally we studied if the children's attitudes, perceived behavioural control, health belief and enjoyment related to sports mediated these associations. Dr. Anna Timperio was first author of this paper, which is yet another product of the cross European Energy project.
More than 7000 children aged 10--12 and one of their parents (6000)  from 175 schools in seven European countries participated. Availability of sport equipment in the home (OR=1.16), financial, logistic and emotional support of the parents for the children to engage in sports, and parental modeling  were all positively associated with the children's participation for more than 30mins/wk is sport activities. Attitude, beliefs, perceived behavioural control and enjoyment partly mediated these associations. These results suggest that parental support both directly and indirectly -i.e. by helping to improve the children's attitudes, feelings of control and enjoyment - promotes sport participation in the children.

Saturday, February 2, 2013

How important is the weather for children's physical activity?

Biking, walking and playing outside is more fun when the sun is out, and it is not too cold? We just published a study, with Mine Yildirim as first author, looking at just that. We used data from our cross-European ENERGY study among 10-12 year olds. We looked at associations between objective data on physical activity and sedentary time -obtained with accelerometers-, with additional data on rainfall and temperature on the exact days in the countries the kids wore their accelerometers. Our results indeed showed that kids moved more with higher temperatures and moved more and sat less with less rainfall.

VUmc research directors visit Brussels

The past two days, a delegation of the research institutes of the Human Health and Life Sciences theme of the VU university and the VU university medical center visit Brussels. We are here to better learn about Horizon2020, i.e. the new research and innovation programmof the European Commission that will be launched in 2014, to get to know the institutions, people and processes who/that are of influence in defining the research agenda and programs, and to present what we have to offer to this agenda. Our research institutes focus on oncology, neurology, cardiovascular disease and public health, and are thus closely linked to the European health research agenda.

Tuesday, January 29, 2013

Childhood obesity conference

Today the Dutch childhood obesity conference was held. This one day conference aims to inform professional in the field of prevention, treatment and care regarding childhood obesity about evidence based practice and new developments and insights in the field. I was invited to deliver a keynote lecture on prevention of overweight and obesity. In my talk I argued (again) that for effective prevention of childhood overweight and obesity a health protection approach -aiming to create and establish a more 'obesopreventive' instead of the present day 'obesogenic'  environment- is needed on top of a health promotion approach leaning heavily on health education and personal responsibility. Overweight and obesity are societal problems and society -at all levels from authorities, the private sector to families and individuals need to take joint responsibility.

Friday, January 25, 2013

Brown fat and ice skating ...

A paper published in the Journal of Clinical Investigation by Ouellet and others last fall drew quite a bit of new attention to the possible role of brown fat in energy balance and obesity prevention. Humans have two types of fat, brown and white. The white stuff is what people who are overweight and obese have too much of. Brown fat is another issue. Brown fat helps to generate body heat in cold circumstances, and by doing so, burns calories. The study in JCI provides convincing evidence for just that. The study suggests that letting ourselves be exposed to cold temperatures may help to maintain a healthy body weight.
These days, the Dutch are letting themselves be exposed to cold temperatures in big numbers. The ice on many canals is thick enough to skate on. This afternoon we managed to avoid the big crowds to do some great skating.

Saturday, January 19, 2013

How do children from lower educated parents differ in health behaviors from their peers?

It is well known that the prevalence of overweight and obesity is considerably higher among schoolchildren from lower socio-economic backgrounds. We recently reported such disparities among school-age children across 7 countries in Europe, and in another recent additional analysis we showed the same for an eight' country, namely Switzerland, that was reported in a recent scientific paper. In the first paper, published in Plos ONE, we also provided further evidence that children from lower educated parents are more likely to engage in behaviors that contribute to their higher risk for overweight and obesity. Now in a further study just published with Juan Fernández-Alvira as first author, we examined whether these behaviors, i.e. sugared drinks intake, physical activity, screen time and usual sleep duration cluster in reliable and meaningful ways among European children, and whether the identified clusters could be characterized by parental education.

We used the data from our ENERGY study, i.e. data from 5284 children (46% male), from the seven European countries. Cluster analysis was performed separately for girls and boys. Associations with parental education were identified using chi-square tests and odds ratios.
Five meaningful and stable clusters were found for both genders. More healthy behavior clusters were more likely among children from higher educated parents, while clusters with high sugared drinks consumption, high screen time and low sleep duration were more prevalent in the group with lower educated parents. 
Children with lower educated parents thus are more likely to engage in different joint behaviors that contribute to higher risk for overweight and obesity.

Sunday, January 13, 2013

who stops sports participation in adolescence?

Many youngsters stop engaging in sports during adolescence. In a study just published in e-pub in the European Journal of Public Health, with Dr. Rick Prins as first author, we explored who is more likely to stop doing sports in this age group. Data were obtained from the Environmental Determinants of Obesity in Rotterdam Schoolchildren (ENDORSE) study, and 357 adolescents were eligible for analysis. We looked at who were more likely to stop engaging in sports altogether, and who were more likely to reduce their sports activities so that they no longer comply to the recommendations to engage in vigorous physical activity to improve fitness for at least 3 time 20 minutes per week. 

Girls, lower-educated adolescents and those with a non-Western background showed more pronounced reductions in sports participation and compliance with the recommendation than boys, youngsters in forms of higher education, and native Dutch adolescents, respectively. Perceived neighborhood safety could partly explain the difference between girls and boys, indicating that one reason girls are more likely to reduce sports is related to feelings of (lack of) safety.

Thursday, January 10, 2013

The cohort profile of the READI study published

The Resilience for Eating and Activity Despite Inequality (READI) cohort was established by the Center for Physical Activity and Nutrition research (C-PAN) at Deakin University, led by Prof. Kylie Ball, to address the following two key aims: to investigate the pathways (personal, social and structural) by which socio-economic disadvantage influences lifestyle choices associated with obesity risk (physical inactivity, poor dietary choices) and to explore mechanisms underlying 'resilience' to obesity risk in socio-economically disadvantaged women and children. A paper describing this innovative cohort study was just published as a cohort profile in the International Journal of Epidemiology. A total of 4349 women aged 18-46 years and 685 children aged 5-12 years were recruited from 80 socio-economically disadvantaged urban and rural neighbourhoods of Victoria, Australia, and provided baseline (T1: 2007-08) measures of adiposity, physical activity, sedentary and dietary behaviours; socio-economic and demographic factors; and psychological, social and perceived environmental factors that might impact on obesity risk. Audits of the 80 neighbourhoods were undertaken at baseline to provide objective neighbourhood environmental data. Three-year follow-up data (2010-11) have recently been collected from 1912 women and 382 children.