Biomedical subjects

Johannes Brug

Publications and source records attributed to Johannes Brug.

At least 19 recordsLinked to original sources

PubMed2006

Moderators of environmental intervention effects on diet and activity in youth.

BACKGROUND: The complexity of the relationship between environmental factors on the one hand and dietary behavior and physical activity on the other necessitates the search for moderators of environmental influences. The current evidence base is reviewed regarding potential moderating factors in the effectiveness of environmental interventions aimed at diet and/or physical activity of children and adolescents. METHODS: The following databases were used: (1) Medline, (2) PubMed, (3) PsychInfo, (4) Web of Science, and (5) ERIC. Additionally, all potentially relevant references in recent reviews were checked. RESULTS: Of the 41 studies included in the review, only seven studies (17%) were identified that reported tests of potential moderators of intervention effects. Gender proved to be the most frequently studied potential moderator. Additionally, race, age, and site have been studied regarding their potential role in modifying the effect of environmental interventions. DISCUSSION: The small number of studies identified in this review prohibited us from attempting to formulate a conclusion on differential environment-behavior relationships in distinct subgroups. Rather than being an exception, it is argued that tests of effect modifiers should become common practice in behavioral nutrition and physical activity research to increase our understanding of mechanisms of behavior change and to optimize interventions.

Adolescent↗

PubMed2006

Design of the Dutch Obesity Intervention in Teenagers (NRG-DOiT): systematic development, implementation and evaluation of a school-based intervention aimed at the prevention of excessive weight gain in adolescents.

BACKGROUND: Only limited data are available on the development, implementation, and evaluation processes of weight gain prevention programs in adolescents. To be able to learn from successes and failures of such interventions, integral written and published reports are needed. METHODS: Applying the Intervention Mapping (IM) protocol, this paper describes the development, implementation, and evaluation of the Dutch Obesity Intervention in Teenagers (DOiT), a school-based intervention program aimed at the prevention of excessive weight gain. The intervention focussed on the following health behaviours: (1) reduction of the consumption of sugar-sweetened beverages, (2) reduction of energy intake derived from snacks, (3) decrease of levels of sedentary behaviour, and (4) increase of levels of physical activity (i.e. active transport behaviour and sports participation). The intervention program consisted of an individual classroom-based component (i.e. an educational program, covering 11 lessons of both biology and physical education classes), and an environmental component (i.e. encouraging and supporting changes at the school canteens, as well as offering additional physical education classes). We evaluated the effectiveness of the intervention program using a randomised controlled trial design. We assessed the effects of the intervention on body composition (primary outcome measure), as well as on behaviour, behavioural determinants, and aerobic fitness (secondary outcome measures). Furthermore, we conducted a process evaluation. DISCUSSION: The development of the DOiT-intervention resulted in a comprehensive school-based weight gain prevention program, tailored to the needs of Dutch adolescents from low socio-economic background.

Adolescent↗

PubMed2006

Adolescent screen-viewing behaviour is associated with consumption of sugar-sweetened beverages: the role of habit strength and perceived parental norms.

The association between adolescent screen-viewing behaviour (i.e., television viewing and computer use) and the consumption of sugar-sweetened beverages was studied in a Dutch sample of adolescents (N=383) using self-administered questionnaires. In particular, the previously understudied role of habit and perceived parental norms in the execution of these behaviours was investigated. Results showed that screen-viewing behaviour was associated with consumption of sugar-sweetened beverages (r=.32). Habit strength of both behaviours correlated with a large effect size (r=.50). The interaction between both behaviours was underlined by the finding that consumption of sugar-sweetened beverages was explained by perceived parental norms regarding screen-viewing behaviour (beta=.12; adjusted for the behaviour and perceived parental norm regarding sugar-sweetened beverage consumption). Consequences of the identified role of habit and parental norms in the interplay between sedentary behaviour and consumption of sugar-sweetened beverages among adolescents are discussed.

Adolescent↗

PubMed2006

Revisiting Kurt Lewin: how to gain insight into environmental correlates of obesogenic behaviors.

Overweight and obesity are important determinants of population health. Prevention of weight gain is dependent on the successful balancing of eating and physical activity behaviors. Planned promotion of healthful behavior requires insights into important and changeable determinants and correlates of behavior change. The modest effects of health education have induced a shift in focus from personal to environmental correlates of eating and physical activity behaviors. Six systematic reviews were conducted in 2005 of observational studies of environmental correlates and environmental interventions for weight-related eating behaviors and physical activity for children, adolescents, and adults. The reviews of 297 observational studies showed that few investigations of environmental associations have been replicated, and that most studies used weak research designs and nonvalidated self-report measures, were restricted to micro-environmental factors, and failed to apply multilevel analyses. There is, therefore, very little evidence for an association between environmental factors and weight-related behaviors. However, the reviews of 112 intervention studies indicated much stronger evidence for positive effects of micro-physical and sociocultural environmental changes on eating and physical activity behaviors. Inspired by quotes from Kurt Lewin, we argue that before large-scale environmental change interventions are launched, better-designed and -conducted research on the true importance of environmental factors, including macrolevel factors, for obesogenic behavioral change is needed. Such research should (1) develop better measures of environmental exposure, (2) attempt to integrate personal and environmental correlates of obesogenic behaviors, (3) take a solution-oriented, rather then a problem-oriented approach, and (4) identify access points for inducing behavior change instead of finding explanations for existing behavioral patterns.

Health Behavior↗

PubMed2006

Personal, social and environmental correlates of vegetable intake in normal weight and overweight 9 to 13-year old boys.

BACKGROUND: The first aim of the present study was to investigate differences in correlates of vegetable intake between the normal weight and the overweight boys in the Pro Children Cross Sectional Study. The second aim was to explore whether the association between vegetable intake and potential correlates is different in overweight boys compared with normal weight boys. METHODS: Random samples of mainly 11-year old children were recruited in 9 European countries. The total sample size consisted of 3960 boys (16.5% overweight). A validated self-report questionnaire was used to measure vegetable intake, and personal, social and environmental factors related to vegetable intake in the classroom. Weight and height were reported by the parents of the children in parents' questionnaires. RESULTS: Regression analyses explained 23% to 28% of the variance in vegetable intake by potential correlates. Liking, self-efficacy and bringing vegetables to school were related to intake in both normal weight and overweight boys (beta's>0.10). Active parental encouragement and availability at home was only related to intake in overweight boys (beta's>0.10), whereas knowledge about recommendations was only related to vegetable consumption in normal weight boys (beta>0.10) CONCLUSION: Intervention strategies to increase vegetable intake should focus on increase in liking and preferences, increase in self-efficacy, and increase in bringing vegetables to school in both normal weight and overweight boys. Further research should investigate whether advising parents of overweight boys to encourage their child to eat vegetables every day, to insist as far as possible that their child eats vegetables regularly and to make vegetables easily available at home is effective in changing vegetable intake.

Journal Article↗

PubMed2006

Comparing stage of change and behavioral intention to understand fruit intake.

We explored if the pre-action Transtheoretical stages of change are indeed discrete stages for fruit intakes. In a longitudinal design, a cohort of 735 adults completed electronic questionnaires assessing fruit intake, stages of change and intention to increase fruit intake at baseline and 35 and 67 days follow-up. A dichotomization of a continuous intention measure ('pseudostages') was compared with precontemplation and contemplation stages. The results showed (i) that pseudostages and stages of change were strongly associated; (ii) that for most respondents, stability and transitions in stages of change resembled transitions in pseudostage, while test-retest reliabilities for both measures were similar and (iii) that pseudostages and the continuous intention measure were stronger predictors of fruit intake than stage of change. We conclude that pre-action stages of change for fruit are not different from a mere categorization of a continuous intention measure.

Adult↗

PubMed2006

Differences in fruit and vegetable intake and determinants of intakes between children of Dutch origin and non-Western ethnic minority children in the Netherlands - a cross sectional study.

BACKGROUND: Fruit and vegetable consumption is low in the Netherlands and a key target in healthy diet promotion. However, hardly any information is available on differences in fruit and vegetable consumption between Dutch children and ethnic minority children. Therefore, the aim of present study was to determine differences in usual fruit and vegetable intake between native Dutch and non-Western ethnic minority children and to study differences in and mediating effects of potential psychosocial and environmental determinants. METHODS: Ethnicity, usual fruit and vegetable consumption, psychosocial and environmental determinants and mothers' educational level were measured with a self-administered questionnaire during school hours in primary schools in Rotterdam, the Netherlands. Complete data was available for 521 10-11 year-old-children, of which 50.5% of non-Western origin. Differences between the groups regarding potential determinants and fruit and vegetable intake were assessed with Mann Whitney tests or multiple regression analyses. Multiple regression analyses were also conducted to assess mediating effects. RESULTS: Ethnic minority girls ate fruit more frequently (1.41 +/- 1.0 times/day) than Dutch girls (1.03 +/- 0.82 times/day); no differences in frequency of intake were found for vegetables or among boys. Ethnic differences were found for almost all potential determinants. The Dutch children reported lower scores on these determinants than the ethnic minority children, except for perceived self-efficacy and barriers to eat fruit and vegetables. Knowledge of recommendations and facilitating behaviors of the parents mediated the association between ethnicity and fruit consumption among girls. CONCLUSION: Ethnic minority girls in the Netherlands appear to have more favorable fruit intakes than Dutch girls, and ethnic minority children in general show more positive prerequisites for fruit and vegetable consumption. Interventions addressing multi-ethnic populations of children must take such differences into account.

Journal Article↗

PubMed2006

Order is needed to promote linear or quantum changes in nutrition and physical activity behaviors: a reaction to 'A chaotic view of behavior change' by Resnicow and Vaughan.

Recently, Drs. Ken Resnicow and Roger Vaughan published a thought-provoking paper in the International Journal of Behavioral Nutrition and Physical Activity (IJBNPA). They argue that the most often used social-cognition theories in behavioral nutrition and physical activity are of limited use. These models describe behavior change as a linear event, while Resnicow and Vaughan posit that behavior change is more likely to occur in quantum leaps that are impossible to predict. They introduce Chaos Theory into the behavioral nutrition and physical activity domain as a more valid framework to study the complex process of health behavior change. The present paper is a commentary on Resnicow and Vaughan's article by Resnicow's opponent in a recent debate-session at the annual meeting of the International Society of Behavioral Nutrition and Physical Activity. The chair of that meeting, Prof. Tom Baranowski, provides a separate commentary on Resnicow and Vaughan's paper also published recently in the IJBNPA. In the present commentary I relate Resnicow and Vaughan's paper to the other contributions to the Theory debate in the IJBNPA. I recognize the limited success of social cognition models, and, next to a better application of these models and more thorough research to test these model, also support research to further test the quantum and chaotic character of health behavior change. However, if such research supports the chaotic and quantum nature of health behavior change, the implications for behavioral nutrition and physical activity interventions may be limited, because even if behavior change is quantum rather than linear, the social cognition models are still relevant to inform interventions to promote quantum leaps in behavior change.

Comment↗

PubMed2006

Krachtvoer: process evaluation of a Dutch programme for lower vocational schools to promote healthful diet.

The aim of this study was to examine the fidelity and completeness of the implementation of a school-based healthful diet promotion programme called 'Krachtvoer' (we use the Dutch title of the programme throughout this article. A possible translation is Power Food, but this does not reflect the play on words in the Dutch title), aimed at lower vocational training students aged 12-14 years. The teachers' and students' opinions of the programme were also assessed, as well as the association between these opinions and the level of implementation. Data were collected through structured teachers' monitoring reports, in-class observations and in-depth interviews with teachers. Further data were drawn from a student questionnaire included in a concurrent cluster-randomized baseline post-test experimental study evaluating the effects of the programme. The present study indicates that the teachers implemented the programme largely according to plan, that the teachers appreciated most parts of the programme and that the students who were exposed to the programme were more appreciative of their nutrition education lessons than students who followed the usual curriculum. However, programme elements that teachers did not like were often not implemented. We conclude that the Krachtvoer programme is a promising tool to encourage students in lower vocational training to adopt diets that are more healthful. The present study revealed the stronger and weaker parts of the programme and can thus guide programme improvement.

Adolescent↗

PubMed2006

Perceived parenting style and practices and the consumption of sugar-sweetened beverages by adolescents.

The purpose of this study was to investigate whether perceived parenting practices and parenting style dimensions (strictness and involvement) are associated with adolescents' consumption of sugar-sweetened beverages. In this cross-sectional study, secondary school students (n = 383, mean age 13.5 years) completed a self-administered questionnaire on their consumption of sugar-sweetened beverages, attitude, social influences, self-efficacy, habit strength, food-related parenting practices and the general parenting style dimensions of 'strictness' and 'involvement'. Data were analyzed using multiple linear regression analyses. More restrictive parenting practices were associated with lower consumption of sugar-sweetened beverages (beta = -38.0 ml; 95% CI = -48.1, -28.0). This association was highly mediated ( approximately 55%) by attitude, self-efficacy and modeling from parents. Nevertheless, a significant direct effect remained (beta = -17.1 ml; 95% CI = -27.2, -6.90). Interactions between perceived parenting style and parenting practices showed that the association between parenting practices and sugar-sweetened beverage consumption was stronger among adolescents who perceived their parents as being moderately strict and highly involved. Parents influence their children's sugar-sweetened beverage consumption and should therefore be involved in interventions aimed at changing dietary behaviors. Interventions aimed at the promotion of healthy parenting practices will improve when they are tailored to the general parenting style of the participants.

Adolescent↗

PubMed2006

Determinants of fruit and vegetable consumption among children and adolescents: a review of the literature. Part I: Quantitative studies.

BACKGROUND: In order to more effectively promote fruit and vegetable intake among children and adolescents, insight into determinants of intake is necessary. We conducted a review of the literature for potential determinants of fruit and vegetable intake in children and adolescents. METHODS: Papers were identified from Medline and PsycINFO by using all combinations of the search terms: "fruit(s) or vegetable(s)" and "children or adolescents". Quantitative research examining determinants of fruit and/or vegetable intake among children and adolescents aged 6-18 years were included. The selection and review process was conducted according to a four-step protocol resulting in information on country, population, design, methodology, theoretical basis, instrument used for measuring intake, statistical analysis, included independent variables, and effect sizes. RESULTS: Ninety-eight papers were included. A large number of potential determinants have been studied among children and adolescents. However, for many presumed determinants convincing evidence is lacking, mostly because of paucity of studies. The determinants best supported by evidence are: age, gender, socio-economic position, preferences, parental intake, and home availability/accessibility. Girls and younger children tend to have a higher or more frequent intake than boys and older children. Socio-economic position, preferences, parental intake, and home availability/accessibility are all consistently positively associated with intake. CONCLUSION: The determinants most consistently supported by evidence are gender, age, socio-economic position, preferences, parental intake and home availability/accessibility. There is a need for internationally comparative, longitudinal, theory-based and multi-level studies taking both personal and environmental factors into account. This paper is published as part of the special Pro Children series in the International Journal of Behavioral Nutrition and Physical Activity. Please see [http://www.ijbnpa.org/content/3/1/26] for the relevant editorial.

Journal Article↗

PubMed2006

Do the transtheoretical processes of change predict transitions in stages of change for fruit intake?

In a longitudinal study, it is examined whether the transtheoretical processes of change do predict stage transitions in fruit intake. A random sample of an existing Internet research panel resulted in a cohort of 735 adults, who were examined three times with electronic questionnaires assessing stages of change, processes of change, and fruit intake. Cross-sectional differences were found for the processes of change between precontemplation and all further stages. Experiential as well as behavioral processes increased from precontemplation to action with similar patterns. Both experiential and behavioral processes predicted forward transition out of precontemplation and forward transition into action, whereas only behavioral processes predicted forward transition out of contemplation. The results indicate that the transtheoretical processes of change predict stage transitions for fruit intake, but that the pattern of relevant processes for fruit intake is not as straightforward as outlined by the transtheoretical model of behavior change.

Adult↗

PubMed2006

Associations of social-environmental and individual-level factors with adolescent soft drink consumption: results from the SMILE study.

Adolescent obesity is positively associated with soft drink consumption. We investigated the association of social-environmental and individual-level factors with soft drink consumption in a Dutch adolescent sample. Data were gathered in a longitudinal Dutch adolescent sample (n = 208, 62% girls). Soft drink consumption, social cognitions from the Theory of Planned Behaviour and parenting practices towards limited soft drink intake, and Big Five personality dimensions were assessed. Data were analyzed using three-step linear regression analyses. Effect sizes were used as the informational source for the explanatory value of the model. Interaction terms were computed to test the individual-environment interaction. Attitude and subjective norm were significantly associated with soft drink consumption. When controlling for social cognitions, the distal variables parenting practices and the personality dimension Agreeableness remained significantly associated with soft drink consumption. Agreeableness moderated the association of parenting practices with adolescent soft drink consumption. Standardized regression coefficients ranged from 0.16 to 0.24 and explained 14% of the variance in soft drink consumption, indicating a medium effect size. Stricter parenting practices were associated with less soft drink consumption and these effects were moderated by adolescent personality. The direct effects of practices and personality are noteworthy from a theoretical perspective. Implications for obesity prevention interventions are discussed.

Adolescent↗

PubMed2006

Parents often do not recognize overweight in their child, regardless of their socio-demographic background.

To involve parents successfully in the treatment of overweight in their child, they first need to be aware of the problem and its accompanying health risks. Data on 1840 9-11 year olds from the Rotterdam Youth Health Monitor were analysed to investigate whether awareness of parents differs according to socio-demographic characteristics. In the case of overweight children, 50% of the parents do not recognize that their child is overweight. Except for age none of the investigated socio-demographic characteristics, including ethnicity and parental education, was associated with awareness. Parents of obese children show greater awareness than parents of overweight children.

Age Factors↗

PubMed2006

Perceived environmental determinants of physical activity and fruit and vegetable consumption among high and low socioeconomic groups in the Netherlands.

A focus group study was conducted to explore how perceptions of environmental influences on health behaviours pattern across socioeconomic groups in the Netherlands. Participants perceived their spouse's and friend's health behaviour and support as highly important. People from lower socioeconomic backgrounds reported poor neighbourhood aesthetics, safety concerns and poor access to facilities as barriers for being physically active, while easy accessibility to sports facilities was mentioned by high socioeconomic participants. The availability of fruits and vegetables at home was perceived as good by all particpants. Overall, lower socioeconomic groups expressed more price concerns. Possible pathways between socioeconomic status, environmental factors and health behaviours are represented in a framework, and they should be investigated further in longitudinal research.

Adult↗

PubMed2006

The Transtheoretical model for fruit, vegetable and fish consumption: associations between intakes, stages of change and stage transition determinants.

BACKGROUND: Cardiovascular diseases are caused by multiple behavioral factors, including different dietary factors. We examined to what extent fruit, vegetable and fish consumption are related, and whether behavioral determinants vary across these dietary behaviors from a Transtheoretical model perspective. METHODS: Data were collected among 1142 participants (T0; response rate 46%) selected from an Internet panel, who were followed-up one-week later (T1; N = 1055, response rate 92%). Mean age was 35.4 (SD = 11.9) years, 35% was male, and most respondents were of Dutch origin (90%). Of the respondents, 13%, 44% and 43% had a low, medium or high level of education, respectively. Electronic questionnaires assessed fruit, vegetable and fish intake (food frequency questionnaires), stages of change, decisional balance and self-efficacy, for each of these three behaviors. RESULTS: Stages of change and (changes in) fruit, vegetable and fish intake were only weakly associated; decisional balance and self-efficacy were more strongly associated. Some presumed predictors of stage transitions were similar for fruit, vegetable, and fish intake, i.e., strong pros predicted progress out of precontemplators and low self-efficacy predicted relapse from action/maintenance for all behaviors. However, progress out of contemplation and out of preparation showed different patterns for fruit, vegetable and fish intake. CONCLUSION: The weak associations between intakes and potential determinants for fruit, vegetable, and fish consumption do not warrant an integrated dietary change approach targeting the same determinants for each behavior.

Journal Article↗

PubMed2006

Environmental influences on energy balance-related behaviors: a dual-process view.

BACKGROUND: Studies on the impact of the 'obesogenic' environment have often used non-theoretical approaches. In this journal's debate and in other papers authors have argued the necessity of formulating conceptual models for differentiating the causal role of environmental influences on behavior. DISCUSSION: The present paper aims to contribute to the debate by presenting a dual-process view on the environment--behavior relationship. This view is conceptualized in the EnRG framework (Environmental Research framework for weight Gain prevention). In the framework, behavior is postulated to be the result of a simultaneous influence of conscious and unconscious processes. Environmental influences are hypothesized to influence behavior both indirectly and directly. The indirect causal mechanism reflects the mediating role of behavior-specific cognitions in the influence of the environment on behavior. A direct influence reflects the automatic, unconscious, influence of the environment on behavior. Specific personal and behavioral factors are postulated to moderate the causal path (i.e., inducing either the automatic or the cognitively mediated environment - behavior relation). In addition, the EnRG framework applies an energy balance-approach, stimulating the integrated study of determinants of diet and physical activity. CONCLUSION: The application of a dual-process view may guide research towards causal mechanisms linking specific environmental features with energy balance-related behaviors in distinct populations. The present paper is hoped to contribute to the evolution of a paradigm that may help to disentangle the role of 'obesogenic' environmental factors.

Journal Article↗

PubMed2006

The 'balance intervention' for promoting caloric compensatory behaviours in response to overeating: a formative evaluation.

To help people prevent weight gain, the Netherlands Nutrition Centre initiated the 'balance intervention', which promotes moderation of food intake and/or increased physical activity in response to occasions of overeating. The aim of this study was to determine whether intervention materials were appreciated, encouraged information seeking and increased motivation and caloric compensatory behaviours. A three-group randomized trial with pre-intervention measures (n = 963, response 86%) and post-intervention measures (n = 857) using electronic questionnaires was conducted among participants aged 25-40 years, recruited from an Internet research panel. The first group received a printed brochure and electronic newsletters (print group), the second group was exposed to radio advertisements (radio group) and the third group was the control group. Multiple regression analyses were used to investigate the impact of the materials on self-reported prevalence of overeating, attitudes, perceived behavioural control, intentions and compensatory behaviours. At follow-up, we found significantly more positive attitudes, intentions and dietary action in the print and radio groups. However, participants who received the radio advertisement had a significantly lower perceived behavioural control. No effects were found on the prevalence of overeating. The results indicate that the intervention materials have potential for increasing people's attitudes, motivation and self-reported behaviour actions, with a possible negative side-effect on perceived behavioural control.

Adult↗