[Nutrition and mental disorders during the life span: an overview of scientific evidence]. / Voeding bij psychische aandoeningen gedurende de levensloop; een overzicht van de evidentie.

BACKGROUND: Nutritional interventions are scarcely used in the prevention and treatment of mental disorders.
AIM: To summarize scientific evidence on the relation between nutrition and mental health, across the life span.
METHOD: An overview of the literature based on recent knowledge syntheses, meta-analyses and original studies.
RESULTS: Healthy dietary patterns are associated with a lower risk for depressive symptoms among adults and potentially also among children and adolescents. Dietary interventions can be effective in reducing depressive symptoms among high-risk groups and can have a beneficial effect in the treatment of depression. Meta-analyses of randomised studies have shown that omega-3 fatty acid supplements can be of added value in the treatment of adhd in children and of depression in adults.
CONCLUSION: Promotion of healthy dietary patterns in line with National guidelines for healthy diets is important in the entire spectrum from good mental health to a chronic disorder. More attention for improving healthy dietary patterns among patients with mental disorders can lead to important health gains.

The introduction of the practice nurse mental health in general practices in the Netherlands: effects on number of diagnoses of chronic and acute alcohol abuse.

BACKGROUND: Since 2008 mental health practice nurses have been gradually introduced in general practices in the Netherlands as part of health policy aiming to improve early identification and treatment of mental health problems in primary care. This study aims to investigate the effect of the introduction of the practice nurse mental health in general practices in the Netherlands on the number of diagnoses of chronic and acute alcohol abuse. METHODS: The Netherlands Institute for Health Services Research (NIVEL) retrieved data of a representative sample of general practices (n = 155) for this study. Data were aligned at the starting point of the implementation of the PN-MH to compare the practices on our outcome measures after implementation of the PN-MH. Multilevel regression analyses were conducted to investigate differences in average number of chronic and acute alcohol abuse diagnoses between practices with a practice nurse mental health and control practices (without a practice nurse mental health and without a primary care psychologists). RESULTS: A significant decrease over time of chronic alcohol abuse diagnoses was observed (ß = -.52, p < 0.05) as well as a significant decrease over time of acute alcohol abuse diagnoses (ß = -.06, p < 0.05). After adjustment for multiple comparisons, no significant differences were found between practices that implemented a practice nurse mental health or only have a primary care psychologist and control practices. Practices that implemented a practice nurse mental health and have a primary care psychologist, had a higher mean of chronic and acute alcohol abuse diagnoses than control practices during all periods, but the differences between these groups were not statistically significant. CONCLUSIONS: Based on the results of this study it seems that the introduction of practice nurses mental health in general practices is not associated with increased diagnoses of chronic or acute alcohol abuse. Potential explanations are barriers experienced by practice nurses to addressing alcohol use with patients and prioritization of other mental health issues over alcohol abuse. In order to improve the management of alcohol abuse by practice nurses, more research is needed on how practice nurses can be involved in diagnosing and treatment of patients with alcohol abuse.

Do general practitioners record alcohol abuse in the electronic medical records? A comparison of survey and medical record data.

OBJECTIVE: Primary care professionals are encouraged to screen patients for alcohol abuse. However, patients with alcohol abuse are often under-diagnosed as well as under-registered in medical records in general practices. This study aims to report on the registration rates of alcohol abuse diagnoses in general practices in comparison to patients' self-reported rates of alcohol use disorder. RESEARCH DESIGN AND METHODS: Data of a total number of 2,349 patients were analyzed from the SMILE study, a large prospective cohort study conducted in The Netherlands. Two data collection strategies were combined: (1) Patient self-report data on alcohol consumption as well as other sociodemographic characteristics; (2) Medical record (ICPC codes) data of diagnoses of chronic and acute alcohol abuse of the same patients. GPs' registrations of diagnoses were compared with the self-report data using descriptive statistics. RESULTS: Based on the results of the patient reported data, 179 (14.8%) male participants had an alcohol use disorder. Of the total number of female patients, 82 (7.2%) had an alcohol use disorder. One of the male and none of the female patients with an alcohol use disorder were registered as such by the GP. CONCLUSIONS: This study found that 11.1% of the total patient sample reported an alcohol use disorder, of which a strikingly low number of patients were recorded as such by their GP. It is likely that low recognition due to barriers related to alcohol screening as well as registration avoidance due to the stigma around alcohol abuse play a role in low registration.

Why do Dutch people use dietary supplements? Exploring the role of socio-cognitive and psychosocial determinants.

BACKGROUND: In the Netherlands, the prevalence of dietary supplement use has doubled (from 17 to 40 per cent) since the 1980s. Yet, limited data is available on which socio-cognitive factors are associated with dietary supplement use. Therefore, the purpose of the study is to explain dietary supplement use with determinants deriving from the Integrated Change Model (ICM) and from formative research. METHOD/DESIGN: Socio-cognitive and psychosocial factors were measured among users and non-users of dietary supplements in a longitudinal survey study, with measurements at baseline (N = 1448) and at one-month follow-up (N = 1161). Negative binomial regression analysis was applied to de data. RESULTS: Intention emerged as the main predictor of dietary supplement use (OR = 1.99). Further predictors of dietary supplement use with smaller effect-sizes were: health regulatory focus (promotion, OR = 1.46), social modelling (OR = 1.44), attitude (pros, OR = 1.37), attitude (cons, OR = 0.87), health locus of control (OR = 0.77), and risk perception (chance of getting ill, OR = 1.22). CONCLUSIONS: Individuals tend to use dietary supplements if they are promotion oriented, notice dietary supplement users in their social environment, estimate their chances of getting ill higher, and have positive attitudes towards dietary supplements. In contrast, non-users believe that external factors affect their health, and hold negative attitudes towards dietary supplements. PRACTICAL IMPLICATIONS: Mapping out individuals' socio-cognitive profile may contribute to the development of online health communication. Based on socio-cognitive and demographical factors, personalised advice can be given about dietary supplement use.

A theory-based implementation program for alcohol screening and brief intervention (ASBI) in general practices: Planned development and study protocol of a cluster randomised controlled trial.

BACKGROUND: Previous studies have shown that alcohol screening and brief intervention (ASBI) in general practices can lead to significant reductions in alcohol consumption among patients, yet ASBI is rarely implemented into routine clinical practice. The aim of this paper is to describe the development and evaluation of an ASBI implementation program aimed at increasing ASBI delivery rates of general practitioners (GPs) and decreasing patients' alcohol consumption. METHODS/DESIGN: This study protocol describes the step-wise development and evaluation of an ASBI implementation program. A four-step method is used to identify relevant determinants of change and intervention components based on the Behaviour Change Wheel and the Theoretical Domains Framework. The program will be evaluated in general practices in The Netherlands in a two-arm cluster randomised controlled trial which investigates the effect of the program on GPs' ASBI delivery behaviour as well as on patients' alcohol consumption. DISCUSSION: Effective theory- and practice-based strategies to implement ASBI in general practices are highly needed. Using a stepwise method we described the development of a program consisting of an e-learning module, a tailored feedback module and environmental support and materials. We hypothesize that this program will result in an increase of GPs' ASBI delivery behaviour. Secondly, we expect an overall decrease in percentage of patients with excessive or problematic alcohol use and a higher proportion of patients from GPs receiving the ASBI implementation program decreasing their alcohol consumption, compared to patients from GPs in the control group. TRIAL REGISTRATION: NTR5539.

Physical and social environmental changes to promote walking among Dutch older adults in deprived neighbourhoods: the NEW.ROADS study.

BACKGROUND: Physical activity is important for healthy ageing, and daily walking is seen as a feasible way to be active at older ages. Yet, many older persons, particularly in lower socioeconomic groups and residing in deprived neighbourhoods, are insufficiently active. Creating a physical and social neighbourhood environment that is more supportive for walking has the potential to improve walking behaviour. Current evidence of the impact of changes to the physical and/or social environmental on walking behaviour is scarce. The aim of the NEW.ROADS study is to design, implement and evaluate changes to the physical and social environment for the purpose of increasing walking behaviour among older residents of deprived neighbourhoods. METHODS: Physical and social environmental interventions were developed by matching scientific evidence on environmental determinants of walking, with input from the target population and stakeholders, and ongoing neighbourhood activities. Specifically, a neighbourhood walking route was designed and marked, and neighbourhood walking groups were organised. These environmental interventions were evaluated in a four-armed experimental study. In addition, the design of the study to evaluate the effect of these environmental changes on walking behaviour is described. DISCUSSION: Designing and implementing environmental interventions is a complex endeavour, challenged by limited available theory and evidence. Input from the target population and professional stakeholders is essential, but may also put constraints on the evaluation. TRIAL REGISTRATION: NTR3800 (registered 9/1/2013).

Strategies to Overcome Barriers to Implementation of Alcohol Screening and Brief Intervention in General Practice: a Delphi Study Among Healthcare Professionals and Addiction Prevention Experts.

Despite the evidence base, alcohol screening and brief intervention (ASBI) have rarely been integrated into routine clinical practice. The aim of this study is to identify strategies that could tackle barriers to ASBI implementation in general practice by involving primary healthcare professionals and addiction prevention experts. A three-round online Delphi study was carried out in the Netherlands. The first-round questionnaire consisted of open-ended questions to generate ideas about strategies to overcome barriers. In the second round, participants were asked to indicate how applicable they found each strategy. Items without consensus were systematically fed back with group median ratings and interquartile range (IQR) scores in the third-round questionnaire. In total, 39 out of 69 (57 %) invited participants enrolled in the first round, 214 participants completed the second round, and 144 of these (67 %) completed the third-round questionnaire. Results show that participants reached consensus on 59 of 81 strategies, such as the following: (1) use of E-learning technology, (2) symptom-specific screening by general practitioners (GPs) and/or universal screening by practice nurses, (3) reimbursement incentives, (4) supportive materials, (5) clear guidelines, (6) service provision of addiction care centers, and (7) more publicity in the media. This exploratory study identified a broad set of strategies that could potentially be used for overcoming barriers to ASBI implementation in general practice and paves the way for future research to experimentally test the identified implementation strategies using multifaceted approaches.

Neighbourhood social capital as a moderator between individual cognitions and sports behaviour among Dutch adolescents.

This study aimed to explore whether individual cognitions and neighbourhood social capital strengthen each other in their relation with engaging in sports at least three times per week. Cross-sectional analyses on data from the last wave of the YouRAction trial (2009-2010, Rotterdam, the Netherlands; baseline response: 98%) were conducted. In total 1129 had data on the last wave questionnaire (93%) and 832 of them had complete data on a self-administered questionnaire on frequency of sports participation, perceived neighbourhood social capital, cognitions (attitude, subjective norm, perceived behavioural control and intention toward sport participation) and demographics. Ecometric methods were used to aggregate perceived neighbourhood social capital to the neighbourhood level. Multilevel logistic regression analyses (neighbourhood and individual as levels) were conducted to examine associations of cognitions, neighbourhood social capital and the social capital by individual cognition interaction with fit norm compliance. If the interaction was significant, simple slopes analyses were conducted to decompose interaction effects. It was found that neighbourhood social capital was significantly associated with fit norm compliance (OR: 5.40; 95% CI: 1.13-25.74). Moreover, neighbourhood social capital moderated the association of attitude, perceived behavioural control and intention with fit norm compliance. The simple slope analyses visualized that the associations of cognitions with fit norm compliance were stronger in case of more neighbourhood social capital. Hence, higher levels of neighbourhood social capital strengthen the associations of attitude, perceived behavioural control and intention in their association with fit norm compliance.

Process evaluation of FATaintPHAT, a computer-tailored intervention to prevent excessive weight gain among Dutch adolescents.

UNLABELLED: Process evaluations can help us to better interpret intervention effects and provide guidance in improving interventions. This study describes the use and appreciation of FATaintPHAT, a computer-tailored intervention to prevent excessive weight gain in adolescents and link these data to the intervention effects. Use and appreciation were assessed among students (12-13 years old) from the intervention group of the FATaintPHAT evaluation study, using computer log (n = 458) and questionnaire data (n = 233, 48% response). Differences in use and appreciation between socio-demographic groups (gender, education, ethnicity, weight category), and associations with behavioural outcomes were analysed using descriptive and regression analyses. The results showed that a majority of the students (81%) was exposed to all intervention modules and 73% reported to have put the advice into practise. Half and one-third of the students appreciated the tailored advice positively and neutrally, respectively. Students attending vocational training appreciated FATaintPHAT better than students attending university preparation education. No associations were found between behavioural outcomes with appreciation and use. In conclusion, the school-based FATainPHAT intervention was used and appreciated well among adolescents. The fact that the intervention was appreciated better among the lower compared with higher educated students indicates that the technique of computer-tailoring is also suitable for lower educated students. TRIAL REGISTRATION: Netherlands Trial Registry, ISRCTN 15743786.

From weight management goals to action planning: identification of a logical sequence from goals to actions and underlying determinants.

BACKGROUND: Weight gain prevention (WGP) among adults who are overweight is an important target in the prevention of obesity. However, little is known about the process from WGP as a goal to successful weight-management. The present study aimed to: (i) gain more insight into this process; (ii) identify cognitive predictors of intention for WGP; and (iii) examine WGP as a potential predictor for the intention to change weight-related behaviours [dietary intake (DI) and physical activity (PA)] and specific action planning. METHODS: In this cross-sectional study, overweight adults [n = 510; body mass index 25-30 kg m(-2); mean (SD) age 48 (9.5) years; 30.8% male] completed an online questionnaire, assessing goal intention for WGP, behavioural intention for DI and PA, planning for change in DI and PA and socio-cognitive correlates. Ordinal regression analyses were used to analyse the data. RESULTS: In 89% of the sample, (parts of) the proposed sequence from goal intention (for WGP), behavioural intention (for DI/PA) and planning (for DI/PA) was observed. Attitude, social norm and perceived control towards WGP, and perceived weight status and risk perception, were associated with intention for WGP. Behaviour-specific perceived control and preferences were more strongly associated with intention to change DI or PA and planning for change than intention for WGP was. CONCLUSIONS: Intention for WGP is important in the process toward weight-management because, for most people, intention for WGP precedes behavioural intention, which precedes planning. Intention for WGP is associated with behavioural intention but behaviour-specific factors are the strongest correlates of behavioural intention and planning.

The association between home environmental variables and soft drink consumption among adolescents. Exploration of mediation by individual cognitions and habit strength.

Soft-drink consumption is one of the important target behaviours for the prevention of excessive weight gain among adolescents. To be able to modify these behaviours in obesity prevention interventions, further understanding of the underlying factors and mediational pathways is required. The present study aimed to explore associations between home environment variables and adolescent soft drink consumption and potential mediation of these associations by individual cognitions derived from the Theory of Planned Behaviour and habit strength. The ENDORSE study (N=1005) provided data on soft drink consumption and on home environment variables related to soft drink consumption (availability, accessibility, parental modelling, and parental rules), cognitive variables (intention, attitude, perceived behaviour control, and parental norm) and habit strength. Multiple mediation analyses were conducted using regression analyses according to the steps described by MacKinnon to assess the association between home environment variables and soft drink consumption and mediation of these associations by cognitive variables and habit strength. The bootstrapping method was used to calculate the confidence intervals. There were significant associations between the home environment variables and soft drink consumption. After inclusion of the mediators the strength of these associations was reduced. In the multiple mediator models, habit strength (39.4-62.6%) and intention (19.1-36.6%) were the strongest mediators. Intention and habit strength partly mediate the associations between home environment factors and soft drink consumption, suggesting that home environment variables influence soft drink consumption both indirectly and directly.

The association between cycling to school and being overweight in Rotterdam (The Netherlands) and Kristiansand (Norway).

Active transportation is a behavior that might contribute to energy balance. However, no clear association between active commuting to school and weight status has been reported in the international literature. Also, new studies indicate that cycling to school might have a greater health potential than walking to school. The purpose of the present study is to assess the potential association between cycling to school and weight status in two European cities, Rotterdam and Kristiansand, where cycling to school remains common. Data from two studies, ENDORSE (Rotterdam) and Youth in Balance (Kristiansand), were used including, respectively, 1361 and 1197 adolescents with mean ages of 14.1 and 14.4 years. The adolescents were categorized as cyclist or non-cyclist based on questionnaires on the usual mode of transportation to school. A total of 25% and 18% were categorized as overweight, and 35% and 31% were categorized as cyclists, in Rotterdam and Kristiansand, respectively. In multilevel logistic analyses, after adjusting for potential moderators, the odds ratios for cyclists being overweight compared with non-cyclists were, respectively, 0.63 (95% CI=0.45-0.89) and 0.52 (95% CI=0.34-0.78) in Rotterdam and Kristiansand. The results presented clearly show a negative association between cycling to school and overweight among adolescents both in Rotterdam and in Kristiansand.

Lifestyle changes and reduction of colon cancer incidence in Europe: A scenario study of physical activity promotion and weight reduction.

BACKGROUND: Across Europe, there are over 300,000 new cases of colorectal cancer annually. Major risk factors include excess body weight (usually expressed by a high body mass index, BMI) and physical inactivity (PA). In this study we modelled the potential long-term effects on colon cancer incidence of changes in prevalence of excess body weight and physical inactivity in seven European countries across Europe with adequate data. METHODS: We addressed the impact of interventions aimed at preventing weight gain and increasing physical activity on colon cancer incidence using the Prevent model as refined in the FP-6 Eurocadet project. Relative risk (RR) estimates were derived from meta-analyses; sex- and country-specific prevalences of BMI and PA were determined from survey data. Models were made for Czech Republic, Denmark, France, Latvia, the Netherlands, Spain and the United Kingdom. RESULTS: In a hypothetical scenario in which a whole population had obtained an ideal weight distribution in the year 2009, up to 11 new cases per 100,000 person-years would be avoided by 2040. The population attributable fractions (PAF) for excess weight were much higher for males (between 13.5% and 18.2%) than for females (2.3-4.6%). In contrast, using the optimum scenario where everybody in Europe would adhere to the recommended guideline of at least 30 min of moderate PA 5d per week, the PAFs for PA in various countries were substantially greater in women (4.4-21.2%) than in men (3.2-11.6%). Sensitivity analyses were performed assuming underreporting of BMI by using self-reports (difference of 5 and 0.8 percent-points in males and females, respectively), using different risk estimates (between 5.8 and 11.5 percent-points difference for BMI for men and women, respectively, and up to 11.6 percent-points difference for PA for women). INTERPRETATION: Changes in lifestyle can indeed result in large health benefits, including for colon cancer. Two interesting patterns emerged: for colon cancer, achieving optimum BMI levels in the population appears to offer the greatest health benefits in population attributable fractions in males, while increased physical activity might offer the greatest fraction of avoidable cancers in females. These observations suggest a sex-specific strategy to colon cancer prevention.

Improving hand hygiene behaviour of nurses using action planning: a pilot study in the intensive care unit and surgical ward.

Compliance with hand hygiene guidelines by hospital physicians and nurses is universally low and there is a need to apply powerful intervention methods from social sciences in order to improve compliance. One method is the formation of implementation intentions (or action planning) in which concrete 'if then' plans are formulated to link an environmental cue with performance of an intended behavioural action. This pilot study explored the practicality and effects of action planning on the hand hygiene behaviour (HHB) of nurses in an ICU and surgical ward of a university teaching hospital. A pre-post test design was used, and 17 nurses were invited to participate. A trained researcher observed HHB of nurses before and three weeks after the intervention in which action plans were formulated. Frequencies were calculated and logistic regression analysis was performed to assess changes in HHB. Of the 17 participants, 10 (seven in surgical ward, three in ICU) had complete data and were included in the analyses. In total, 283 potential moments for hand hygiene were identified, 142 in the surgical ward and 141 in the ICU. HHB increased from 9.3% at baseline to 25.4% post intervention (odds ratio: 3.3; confidence interval: 1.7-6.5; P<0.001). Although this was a small scale study, the results show promise for the use of action planning to improve the HHB of nurses in the short term. Action planning has shown success in closing the intention-behaviour gap in other fields, and its use for improving HHB in healthcare should be further investigated.

A qualitative exploration of reasons for poor hand hygiene among hospital workers: lack of positive role models and of convincing evidence that hand hygiene prevents cross-infection.

OBJECTIVE: To study potential determinants of hand hygiene compliance among healthcare workers in the hospital setting. DESIGN: A qualitative study based on structured-interview guidelines, consisting of 9 focus group interviews involving 58 persons and 7 individual interviews. Interview transcripts were subjected to content analysis. SETTING: Intensive care units and surgical departments of 5 hospitals of varying size in The Netherlands. PARTICIPANTS: A total of 65 nurses, attending physicians, medical residents, and medical students. RESULTS: Nurses and medical students expressed the importance of hand hygiene for preventing of cross-infection among patients and themselves. Physicians expressed the importance of hand hygiene for self-protection, but they perceived that there is a lack of evidence that handwashing is effective in preventing cross-infection. All participants stated that personal beliefs about the efficacy of hand hygiene and examples and norms provided by senior hospital staff are of major importance for hand hygiene compliance. They further reported that hand hygiene is most often performed after tasks that they perceive to be dirty, and personal protection appeared to be more important for compliance that patient safety. Medical students explicitly mentioned that they copy the behavior of their superiors, which often leads to noncompliance during clinical practice. Physicians mentioned that their noncompliance arises from their belief that the evidence supporting the effectiveness of hand hygiene for prevention of hospital-acquired infections is not strong. CONCLUSION: The results indicate that beliefs about the importance of self-protection are the main reasons for performing hand hygiene. A lack of positive role models and social norms may hinder compliance.

SARS knowledge, perceptions, and behaviors: a comparison between Finns and the Dutch during the SARS outbreak in 2003.

BACKGROUND: The SARS outbreak served to test both local and international outbreak management and risk communication practices. PURPOSE: The study compares SARS knowledge, perceptions, behaviors, and information between Finns and the Dutch during the SARS outbreak in 2003. METHOD: The participants of the study, who used a modified SARS Psychosocial Research Consortium survey, were drawn from Internet panels in Finland (n = 308) and the Netherlands (n = 373) in June 2003. Multiple logistic regression analyses were used to calculate odds ratios (with 95% confidence intervals) to compare Finns with the Dutch for various levels of perceptions and behaviors. RESULTS: Adjusted for age, education, and income, Finns were more likely to be knowledgeable and worried about SARS as well as to have low perceived comparative SARS risk and poor personal efficacy beliefs about preventing SARS. Finns were also more likely than the Dutch to have high confidence in physicians on SARS issues but less likely to have received information from the Internet and have confidence in Internet information. CONCLUSIONS: The study shed light on how two European populations differed substantially regarding lay responses to SARS. Understanding these differences is needed in formulating and executing communication and outbreak management.

A systematic review of the evidence regarding efficacy of obesity prevention interventions among adults.

In the past, interventions aimed at reducing obesity have mainly targeted at weight loss treatment in obese adults, with limited long-term effects. With the increasing number of people being obese and being at risk for obesity, there has been a shift in focus towards prevention of obesity. We conducted a systematic review of the peer-reviewed literature on the efficacy of obesity prevention interventions in adults in order to identify effective interventions and intervention elements. Pubmed, OVID, and Web of Science databases were searched from January 1996 to June 2006. Interventions aimed at primary prevention of weight gain among adults achieved by focusing on dietary intake, physical activity or the combination of both were included. The outcome measure had to be difference in change in body mass index or body weight between the intervention and the control groups. Nine studies were included, five long-term studies (at least 1 year) and four short-term (3 months to 1 year). Seven studies evaluated an intervention that focused on a combination of diet and physical activity to prevent weight gain, one on diet only and one on physical activity only. One dietary intervention (long-term), and three combined dietary and physical activity interventions (one long-term and two short-term) produced significantly positive results at end of follow-up. The two long-term, effective interventions consisted of intensive and long-term intervention implementation, including groups sessions designed to promote behavioural changes. The current evidence of efficacy of obesity prevention interventions is based on a very small number of studies. Some studies showed a positive impact on body mass index or weight status, but there was too much heterogeneity in terms of study design, theoretical underpinning and target population to draw firm conclusions about which intervention approaches are more effective than others. More research is urgently needed to extend the body of evidence.

A systematic review of environmental correlates of obesity-related dietary behaviors in youth.

There is increasing interest in the role the environment plays in shaping the dietary behavior of youth, particularly in the context of obesity prevention. An overview of environmental factors associated with obesity-related dietary behaviors among youth is needed to inform the development of interventions. A systematic review of observational studies on environmental correlates of energy, fat, fruit/vegetable, snack/fast food and soft drink intakes in children (4-12 years) and adolescents (13-18 years) was conducted. The results were summarized using the analysis grid for environments linked to obesity. The 58 papers reviewed mostly focused on sociocultural and economical-environmental factors at the household level. The most consistent associations were found between parental intake and children's fat, fruit/vegetable intakes, parent and sibling intake with adolescent's energy and fat intakes and parental education with adolescent's fruit/vegetable intake. A less consistent but positive association was found for availability and accessibility on children's fruit/vegetable intake. Environmental factors are predominantly studied at the household level and focus on sociocultural and economic aspects. Most consistent associations were found for parental influences (parental intake and education). More studies examining environmental factors using longitudinal study designs and validated measures are needed for solid evidence to inform interventions.

Underestimation and overestimation of personal weight status: associations with socio-demographic characteristics and weight maintenance intentions.

OBJECTIVE: Unwarranted underestimation and overestimation of personal weight status may prevent weight maintenance behaviour. The present study reports on correlates of under- and overestimation of personal weight status and the association with weight maintenance intentions and self-reported action. DESIGN: Comparison of three cross-sectional surveys, representing different population groups. SUBJECTS: Survey 1: 1694 adolescents 13-19 years of age; survey 2: 979 nonobese adults 25-35 years of age; survey 3: 617 adults 21-62 years of age. MEASUREMENTS: Self-administered written questionnaires (surveys 1 and 3) and telephone-administered questionnaires (survey 2); self-reported BMI, self-rated weight status, intentions and self-reported actions to avoid weight gain or to lose weight, sex, age, education and ethnic background. Respondents were classified as people who are realistic about personal body weight status or people who under- and overestimate their body weight status, based on BMI and self-rated weight status. RESULTS: Most respondents in the three survey populations were realistic about their weight status. Overestimation of weight status was consistently more likely among women, whereas underestimation was more likely among men, older respondents and respondents from ethnic minorities. Self-rated weight status was a stronger correlate of intentions and self-report actions to avoid weight gain than weight status based on Body Mass Index. CONCLUSIONS: Relevant proportions of the study populations underestimated or overestimated their bodyweight status. Overestimation of personal weight status may lead to unwarranted weight maintenance actions, whereas underestimation may result in lack of motivation to avoid further weight gain.

The internet and nutrition education: challenges and opportunities.

OBJECTIVE: To review the possibilities of using the Internet and especially the World Wide Web (WWW) in nutrition education. RESULTS: A healthy existence is partly dependent on dietary behaviours. One way to promote health-promoting dietary habits is nutrition education. In the last decades several potentially important new channels for health communication and nutrition education have emerged, with the Internet and its WWW as the most striking example. The introduction and growth of the WWW has enabled swift and inexpensive distribution of nutrition education expertise and materials. Furthermore, the WWW has also been used for tailoring nutrition education to the personal characteristics of the user. Only few studies have investigated the effects of generic web-based nutrition education, while web-based computer-tailored nutrition education has been studied in randomised controlled trials, with promising but mixed results. Two important challenges for web-based nutrition education interventions are to realise sufficient exposure and to ensure sufficient source reliability and credibility. CONCLUSIONS: Next to the great opportunities, there are many challenges for web-based nutrition education. Some evidence for effects of web-based computer-tailored nutrition education has been reported, but more research is needed to obtain evidence for the effectiveness in real-life situations.