The importance of parental involvement in school-based programs to promote healthy nutrition and physical activity

Parental involvement is often advocated as important for school-based interventions, because parents are a main determinant of children's dietary and physical activity behaviors. We conducted a systematic review of the available scientific literature on this issue to explore the available scientific evidence for this claim. This review thus aimed at determining the impact of parental involvement in school-based obesity prevention interventions in children and adolescents. Our review was conducted as part of the ENERGY project, a European Commission-funded project to improve obesity prevention among school-aged children across Europe. The review was just published in the International Journal of Public Health. Wendy van Lippevelde, a PhD candidate from the University of Ghent was first author.
Akltough some positive effects of parental involvement were found on children's behaviours and behavioural determinants, the evidence was inconclusive. Maybe the most prominebt outcome of our review was that so few studies have been conducted that have explicetely tested the effect of parental involvement, and celarly more studies are needed to address this important issue.  There is a need for more studies comparing school-based interventions with and without a parental component, and dose, strategies and content of parental components of school-based interventions should be better reported in research articles.

Genetic and environmental Influences on screen-time behaviors among adolescents

In a paper with Dr.Niels van der Aa as first author, just published online by Arcives of Pediatric and Adolescent Medicine, we report on an investigation of the genetic and environmental influences on sedentary behavior, i.e. TV and computer time, among adolescents. The paper is based on analyes of cross sectional data from the Netherlands Twin Registrer. The Netherlands Twin Register (NTR) was established in 1987 at the Vrije Universiteit in Amsterdam for scientific research purposes. The study of twins and their family members can provide insight into what extent the causes of differences between individuals are determined by genetic and environmental influences. Prof. Dorret Boomsma, (or see her EMGO personal page) co-author of the paper, is the founder of this registry.

The study published in Archives shows that differences in sedentary behavior can to a large extend be explained by genetic factors, and that the importance of genetic influence increases from age 12 to age 20. To be a bit more specific, our data showed that variation in adolescent sedentary behavior was largely accounted for by genetic and nonshared environmental factors, whereas shared environmental factors account for a substantial part of the variation among younger adolescents. The shift from shared environmental factors in the etiology of sedentary behavior among younger adolescents to genetic and nonshared environmental factors among older adolescents has consequences for intervention programs that aim to reduce adolescents' screen-tme behaviors. These require specific tailoring to age groups and need to focus on peers and parents in early adolescence but on the youngsters themselves at later ages.

Screen time predicts weight gain but body fatness did not predict more screen time in boys

Screen time, i.e. TV viewing and computer time, has been found to be associated with overweight in children and adolescents. However, it is unclear if kids who are overweight start watching more TV or if kids who watch more TV are more likley to become overweight. The aim of a study just published in the International Journal of Behavioral Nutrition & Physical Activity examined the direction of the association between screen time and body fatness in Dutch adolescents. Dr. Teatske Altenburg was first author.

Longitudinal data of 465 Dutch adolescents (mean age at baseline 13 years, 53% boys) was used. Body fatness (objectively measured Body Mass Index (BMI), four skin folds and waist- and hip circumference), self-reported time spent watching TV and computer use, and aerobic fitness (shuttle run test) were assessed in all participants at three time points during 12 months. State of the art statistical analyses were conducted to see if screen time predicted body fatness in the following time period and/or whether body fatness predicted more screen time.

Time spent TV viewing did indeed predict changes in BMI and hip circumference in boys, but not in girls, in the subsequent period. Computer time significantly predicted increases in skinfolds in boys and girls and increases in BMI in girls. Body fatness did not predict any changes in screen time.
Our study thus only partly supports the widely posited hypothesis that more  screen time cause increases in body fatness. In addition, this study demonstrates that high levels of body fatness did not predict increases in screen time.

A review of worksite physical activity promotion interventions in Europe

In a paper just published in e-pub in Obesity Facts, we reviewed the effectiveness of physical activity promotion interventions in the worksite setting in Europe. Studies included (n = 33) were divided in 6 intervention categories. Moderate evidence of effectiveness was found for physical fitness outcomes with exercise training interventions and for physical activity outcomes with active commuting interventions. Although our review suggested that worksite interventions did result in more physical activity, our review showed no or inconclusive evidence for obesity-related outcomes for all intervention categories. We concluded that active commuting and exercise training appear as promising approaches to promote physical activity or fitness in the workplace. The effect of interventions on obesity-related outcomes remains to be further investigated.

Differences in fruit and vegetable intake among Dutch schoolchildren between 2003 and 2009

Fruit and vegetable (FV) intake in children in the Netherlands is much lower than recommended. Recurrent appraisal of intake levels is important for detecting changes in intake over time and to inform future interventions and policies. The aim of a study recently published in the International Journal of Behavioral Nutrition & Physical Activity was to investigate differences in fruit and vegetable intake, and whether these could be explained by differences in potential determinants of FV intake in 11-year-old Dutch schoolchildren, by comparing two school samples assessed in 2003 and 2009 in tow European Commission funded projects, i.e. the Pro Children and Pro Greens projects. In 2009, more children complied with the World Health Organization recommendation of 400g fruit and vegetables per day (17.0%) than in 2003 (11.8%). This difference was mainly explained by a difference in the parental demand regarding their child's intake, by differences in children's knowledge of recommended fruit intake levels and by whether parents faciliated their child's fruit intake. Vegetable intake was lower in the 2009 sample than in the 2003 sample but this difference could not be explained by the assessed mediators. The findings indicate that fruit intake among 11-year-olds improved somewhat between 2003 and 2009. Vegetable intake, however, appears to have declined somewhat between 2003 and 2009. Since a better knowledge of the recommendation, parental demand and facilitation explained most of the observed fruit consumption difference, future interventions may specifically address these potential mediators.

In memoriam: Prof. Marci Campbell

Early this week I received notification of the terrible news that Prof. Marci Campbell, professor at the department of nutrition at the UNC School of Global Public Health of the University of North Carolina at Chapell hill died of cancer.

Dr. Campbell’s research focused on nutrition behavior change for health promotion and disease prevention. Her research focused on investigating health communication strategies aimed at reducing risk factors for cancer and chronic diseases in minority and under-served communities. Approaches include testing effectiveness and cost-effectiveness of computer-generated, individually tailored interventions on diet, physical activity, and cancer screening behaviors for health promotion and disease prevention in diverse populations; impact of multi-level interventions including individual, social, organization and environmental approaches to address social and economic determinants and encourage healthy behaviors; and dissemination research using evidence-based interventions for obesity prevention and health promotion on a population-wide level.

I worked closely with Marci when I took my first steps in research. I was fortunate enough to spend a few months at the University of North Carolina in the early 1990’s when Marci and I were both working on our PhD theses in which we studied the development, implementation and effects of computer-tailored nutrition education. Marci published the first paper on this topic in the American Journal of Public Health. Since then Marci and I kept collaborating on a number of studies, including a reviews in the American Journal of Clinical Nutrition and in Patient Education and Counceling, and as co-advisors for the PhD research of Dr. Willemieke Kroeze, who went on to further explore and improve computer-tailored health education.

Marci was a great friend and colleague and I am grateful that I could work and spent time with her.

New book on writing health communications

This week a new book on writing health communication is out. The book, edited by prof. Charles Abraham of the University of Sussex and Dr. Marieke Kools of Maastricht University. The book provides a systematic and detailled description with lots of practical information regarding how people process information and how such insights can be used to improve health education materials. The book has chapters on message framing, the use of fear appeals, tailoring messages, using graphics, and behaviour change. Each chapter is illustrated with examples - including both good and bad practice and covering a range of health topics. Together with Anke Oenema of Maastricht University, I wrote the chapter on computer-tailored health education.