A short dutch questionnaire to measure fruit and vegetable intake: relative validity among adults and adolescents

The use of a proactive dissemination strategy to optimize reach of an internet-delivered computer tailored lifestyle intervention

Background

The use of reactive strategies to disseminate effective Internet-delivered lifestyle interventions restricts their level of reach within the target population. This stresses the need to invest in proactive strategies to offer these interventions to the target population. The present study used a proactive strategy to increase reach of an Internet-delivered multi component computer tailored intervention, by embedding the intervention in an existing online health monitoring system of the Regional Public Health Services in the Netherlands.

Methods

The research population consisted of Dutch adults who were invited to participate in the Adult Health Monitor (N = 96,388) offered by the Regional Public Health Services. This Monitor consisted of an online or a written questionnaire. A prospective design was used to determine levels of reach, by focusing on actual participation in the lifestyle intervention. Furthermore, adequacy of reach among the target group was assessed by composing detailed profiles of intervention users. Participants’ characteristics, like demographics, behavioral and mental health status and quality of life, were included in the model as predictors.

Results

A total of 41,155 (43%) people participated in the Adult Health Monitor, of which 41% (n = 16,940) filled out the online version. More than half of the online participants indicated their interest (n = 9169; 54%) in the computer tailored intervention and 5168 participants (31%) actually participated in the Internet-delivered computer tailored intervention. Males, older respondents and individuals with a higher educational degree were significantly more likely to participate in the intervention. Furthermore, results indicated that especially participants with a relatively healthier lifestyle and a healthy BMI were likely to participate.

Conclusions

With one out of three online Adult Health Monitor participants actually participating in the computer tailored lifestyle intervention, the employed proactive dissemination strategy succeeded in ensuring relatively high levels of reach. Reach among at-risk individuals (e.g. low socioeconomic status and unhealthy lifestyle) was modest. It is therefore essential to further optimize reach by putting additional effort into increasing interest in the lifestyle intervention among at-risk individuals and to encourage them to actually use the intervention.

Trial registration

Dutch Trial Register (NTR1786) and Medical Ethics Committee of Maastricht University and the University Hospital Maastricht (NL2723506809/MEC0903016).

Reproducibility and relative validity of a brief quantitative food frequency questionnaire for assessing fruit and vegetable intakes in North-African women

BACKGROUND

In the context of a rapidly increasing prevalence of noncommunicable diseases, fruit and vegetables could play a key preventive role. To date, there is no rapid assessment tool available for measuring the fruit and vegetable intakes of North-African women. The present study aimed to investigate the reproducibility and relative validity of an eight-item quantitative food frequency questionnaire that measures the fruit and vegetable intakes (FV-FFQ) of Moroccan women.

METHODS

During a 1-week period, 100 women, living in the city of Rabat, Morocco (aged 20-49 years) completed the short FV-FFQ twice: once at baseline (FV-FFQ1) and once at the end of the study (FV-FFQ2). In the mean time, participants completed three 24-h dietary recalls. All questionnaires were administered by interviewers. Reproducibility was assessed by computing Spearman's correlation coefficients, intraclass correlation (ICC) coefficients and kappa statistics. Relative validity was assessed by computing Wilcoxon signed-rank tests and Spearman's correlation coefficients, as well as by performing Bland-Altman plots.

RESULTS

In terms of reproducibility, Spearman's correlation coefficient was 0.56; ICC coefficient was 0.68; and weighted kappa was 0.35. In terms of relative validity, compared with the three 24-h recalls, the FV-FFQ slightly underestimated mean fruit and vegetable intakes (-10.9%; P = 0.006); Spearman's correlation coefficient was 0.69; at the individual level, intakes measured by the FV-FFQ were between 0.39 and 2.19 times those measured by the 24-h recalls.

CONCLUSIONS

The brief eight-item FV-FFQ is a reliable and relatively valid tool for measuring mean fruit and vegetable intakes at the population level, although this is not the case at the individual level.

Clustering of diet- and activity-related parenting practices: cross-sectional findings of the INPACT study

Background

Various diet- and activity-related parenting practices are positive determinants of child dietary and activity behaviour, including home availability, parental modelling and parental policies. There is evidence that parenting practices cluster within the dietary domain and within the activity domain. This study explores whether diet- and activity-related parenting practices cluster across the dietary and activity domain. Also examined is whether the clusters are related to child and parental background characteristics. Finally, to indicate the relevance of the clusters in influencing child dietary and activity behaviour, we examined whether clusters of parenting practices are related to these behaviours.

Methods

Data were used from 1480 parent–child dyads participating in the Dutch IVO Nutrition and Physical Activity Child cohorT (INPACT). Parents of children aged 8–11 years completed questionnaires at home assessing their diet- and activity-related parenting practices, child and parental background characteristics, and child dietary and activity behaviours. Principal component analysis (PCA) was used to identify clusters of parenting practices. Backward regression analysis was used to examine the relationship between child and parental background characteristics with cluster scores, and partial correlations to examine associations between cluster scores and child dietary and activity behaviours.

Results

PCA revealed five clusters of parenting practices: 1) high visibility and accessibility of screens and unhealthy food, 2) diet- and activity-related rules, 3) low availability of unhealthy food, 4) diet- and activity-related positive modelling, and 5) positive modelling on sports and fruit. Low parental education was associated with unhealthy cluster 1, while high(er) education was associated with healthy clusters 2, 3 and 5. Separate clusters were related to both child dietary and activity behaviour in the hypothesized directions: healthy clusters were positively related to obesity-reducing behaviours and negatively to obesity-inducing behaviours.

Conclusion

Parenting practices cluster across the dietary and activity domain. Parental education can be seen as an indicator of a broader parental context in which clusters of parenting practices operate. Separate clusters are related to both child dietary and activity behaviour. Interventions that focus on clusters of parenting practices to assist parents (especially low-educated parents) in changing their child’s dietary and activity behaviour seems justified.

Can multiple lifestyle behaviours be improved in people with familial hypercholesterolemia? Results of a parallel randomised controlled trial

OBJECTIVE

To evaluate the efficacy of an individualised tailored lifestyle intervention on physical activity, dietary intake, smoking and compliance to statin therapy in people with Familial Hypercholesterolemia (FH).

METHODS

Adults with FH (n = 340) were randomly assigned to a usual care control group or an intervention group. The intervention consisted of web-based tailored lifestyle advice and face-to-face counselling. Physical activity, fat, fruit and vegetable intake, smoking and compliance to statin therapy were self-reported at baseline and after 12 months. Regression analyses were conducted to examine between-group differences. Intervention reach, dose and fidelity were assessed.

RESULTS

In both groups, non-significant improvements in all lifestyle behaviours were found. Post-hoc analyses showed a significant decrease in saturated fat intake among women in the intervention group (β = -1.03; CI -1.98/-0.03). In the intervention group, 95% received a log on account, of which 49% logged on and completed one module. Nearly all participants received face-to-face counselling and on average, 4.2 telephone booster calls. Intervention fidelity was low.

CONCLUSIONS

Individually tailored feedback is not superior to no intervention regarding changes in multiple lifestyle behaviours in people with FH. A higher received dose of computer-tailored interventions should be achieved by uplifting the website and reducing the burden of screening questionnaires. Counsellor training should be more extensive.

TRIAL REGISTRATION

Dutch Trial Register NTR1899.

Associations of children's appetitive traits with weight and dietary behaviours in the context of general parenting

BACKGROUND

Individual variations in child weight can be explained by genetic and behavioural susceptibility to obesity. Behavioural susceptibility can be expressed in appetite-related traits, e.g. food responsiveness. Research into such behavioural factors is important, as it can provide starting points for (preventive) interventions.

OBJECTIVES

To examine associations of children's appetitive traits with weight and with fruit, snack and sugar-sweetened beverage intake, and to examine whether parenting style interacts with appetite in determining child weight/intake.

METHODS

Data were used from 1275 children participating in the INPACT study in 2009-2010, with a mean age of 9 years in 2009. Their height and weight were measured to calculate body mass index (BMI). Parents completed a questionnaire to measure children's appetitive traits, children's dietary intake and parenting style. Child BMI z-scores, fruit, snack and sugar-sweetened beverage intake were regressed on appetitive traits. Moderation by parenting style was tested by adding interaction terms to the regression analyses.

RESULTS

Food-approaching appetitive traits were positively, and food-avoidant appetitive traits were negatively related to child BMI z-scores and to child fruit intake. There were no or less consistent associations for snack and sugar-sweetened beverage intake. Authoritative parenting voided the negative association between food fussiness and fruit intake, while neglecting parenting strengthened the positive association between food-approaching appetitive traits and weight.

CONCLUSIONS

Early assessment of appetitive traits could be used to identify children at risk for overweight. As parenting style can moderate the associations between appetitive traits and weight/intake in a favourable way, parents are a promising target group for preventive interventions aimed at influencing the effect of appetitive traits on children.

Examining the relationship between completeness of teachers’ implementation of the Krachtvoer healthy diet programme and changes in students’ dietary intakes

Objective

The goal of the current study was to examine if the completeness of programme implementation and the completeness of implementation of specific programme elements of the Dutch school-based healthy diet promotion programme Krachtvoer are related to short- and longer-term changes in students’ fruit, sweets and breakfast intakes.

Design

Data on students’ dietary intakes were collected 1–4 weeks and 6 months after programme implementation. Teachers filled in a logbook on programme implementation after each lesson. The relationships between changes in students’ dietary intakes and completeness of implementation of the programme and of specific programme elements were tested using mixed linear regression analyses.

Setting

Thirteen Dutch prevocational schools.

Subjects

Eight hundred and seventy-six of the 1117 participating students and eighteen of the twenty-two participating teachers.

Results

Completeness of programme implementation was positively related to an increase in fruit consumption in the short term. Completeness of implementation of food exposure activities and a practical lesson on advertisements were related to an increase in fruit consumption in the short as well as the longer term. No such relationships were found for sweets and breakfast consumption.

Conclusions

Our results indicate that efforts should be made to help teachers implement the programme as fully as possible.

Reliability and validity of child/adolescent food frequency questionnaires that assess foods and/or food groups

OBJECTIVE

Summarize the validity and reliability of child/adolescent food frequency questionnaires (FFQs) that assess food and/or food groups.

METHODS

We performed a systematic review of child/adolescent (6-18 years) FFQ studies published between January 2001 and December 2010 using MEDLINE, Cochrane Library, PsycINFO, and Google Scholar. Main inclusion criteria were peer reviewed, written in English, and reported reliability or validity of questionnaires that assessed intake of food/food groups. Studies were excluded that focused on diseased people or used a combined dietary assessment method. Two authors independently selected the articles and extracted questionnaire characteristics such as number of items, portion size information, time span, category intake frequencies, and method of administration. Validity and reliability coefficients were extracted and reported for food categories and averaged across food categories for each study.

RESULTS

Twenty-one studies were selected from 873, 18 included validity data, and 14 included test-retest reliability data. Publications were from the United States, Europe, Africa, Brazil, and the south Pacific. Validity correlations ranged from 0.01 to 0.80, and reliability correlations ranged from 0.05 to 0.88. The highest average validity correlations were obtained when the questionnaire did not assess portion size, measured a shorter time span (ie, previous day/week), was of medium length (ie, ≈ 20-60 items), and was not administered to the child's parents.

CONCLUSIONS

There are design and administration features of child/adolescent FFQs that should be considered to obtain reliable and valid estimates of dietary intake in this population.

The effects of Hartcoach, a life style intervention provided by telephone on the reduction of coronary risk factors: a randomised trial

Background

Cardiovascular disease (CVD) is the leading cause of death worldwide. Secondary prevention is essential, but participation rates for cardiac rehabilitation are low. Furthermore, current programmes do not accomplish that patients with CVD change their lifestyle in a way that their individual risk factors for recurrent events decrease, therefore more effective interventions are needed. In this study, the effectiveness of the Hartcoach-programme, a telephonic secondary prevention program focussing on self management, is studied.

Methods/design

A multicenter, randomised parallel-group study is being conducted. Participants are 400 patients with acute myocardial infarction (STEMI, NSTEMI,) and patients with chronic or unstable angina pectoris (IAP). Patients are recruited through the participating hospitals and randomly assigned to the experimental group (Hartcoach-programme plus usual care) or the control group (usual care).

The Hartcoach-programme consists of a period of six months during which the coach contacts the patient every four to six weeks by telephone. Coaches train patients to take responsibility for the achievement and maintenance of the defined target levels for their particular individual modifiable risk factors. Target levels and treatment goals are agreed by the nurse and patient together. Data collection is blinded and occurs at baseline and after 26 weeks (post-intervention). Primary outcome is change in cardiovascular risk factors (cholesterol, body mass index, waist circumference, blood pressure, physical activity and diet). Secondary outcomes include chances in glucose, HbA1c, medication adherence, self-management and quality of life.

Discussion

This study evaluates the effects of the Hartcoach-programme on the reduction of individual risk factors of patients with CVDs. Patients who are not invited to follow a hospital based rehabilitation programme or patients who are unable to adhere to such a programme, may be reached by this home based Hartcoach-programme. If positive results are found, the implementation of the Hartcoach-programme will be extended, having implications for the management of many people with CVD.

Trial registration

NTR2388

Associations between neighbourhood and household environmental variables and fruit consumption: exploration of mediation by individual cognitions and habit strength in the GLOBE study

OBJECTIVE

The present study examined associations of several home and neighbourhood environmental variables with fruit consumption and explored whether these associations were mediated by variables derived from the Theory of Planned Behaviour (TPB) and by habit strength.

DESIGN

Data of the Dutch GLOBE study on household and neighbourhood environment, fruit intake and related factors were used, obtained by self-administered questionnaires (cross-sectional), face-to-face interviews and audits.

SETTING

The city of Eindhoven in the Netherlands

SUBJECTS

Adults (n 333; mean age 58 years, 54% female).

RESULTS

Multiple mediation analyses were conducted using regression analyses to assess the association between environmental variables and fruit consumption, as well as mediation of these associations by TPB variables and by habit strength. Intention, perceived behaviour control, subjective norm and habit strength were associated with fruit intake. None of the neighbourhood environmental variables was directly or indirectly associated with fruit intake. The home environmental variable 'modelling behaviour by family members' was indirectly, but not directly, associated with fruit intake. Habit strength and perceived behaviour control explained most of the mediated effect (71.9%).

CONCLUSIONS

Modelling behaviour by family members was indirectly associated with fruit intake through habit strength and perceived behaviour control. None of the neighbourhood variables was directly or indirectly, through any of the proposed mediators, associated with adult fruit intake. These findings suggest that future interventions promoting fruit intake should address a combination of the home environment (especially modelling behaviour by family members), TPB variables and habit strength for fruit intake.

Healthier food choices as a result of the revised healthy diet programme Krachtvoer for students of prevocational schools

BACKGROUND

Krachtvoer is a Dutch healthy diet programme for prevocational schools, developed in 2001 and revised for a broader target group in 2007, based on the findings of an evaluation of the first version. The goal of this study was to report on the short- and longer-term total and subgroup effects of the revised programme on students' fruit, fruit juice, breakfast, and snack consumption.

METHODS

Schools were randomized to the experimental condition, teaching the Krachtvoer programme, or to the control condition teaching the regular nutrition lessons. Self-reported consumption of fruit, fruit juice, breakfast and snacks was measured at baseline directly before programme implementation, one to four weeks after finishing programme implementation, and after six months. Mixed linear and logistic regression analyses were conducted.

RESULTS

In total 1117 students of 13 experimental schools and 758 students of 11 control schools participated in the study. Short- and longer-term favourable intervention effects were found on fruit consumption (mean difference between experimental and control group 0.15 servings at both posttests). Regarding fruit juice consumption, only short-term favourable effects were revealed (mean difference between experimental and control group 0.05 glasses). Intervention effects on breakfast intakes were limited. No changes in snack frequency were reported, but students made healthier snack choices as a result of the programme. Some favourable as well as unfavourable effects occurred in subgroups of students.

CONCLUSIONS

The effects on fruit consumption and snack choices justify the current nationwide dissemination of the programme. Achieving changes in breakfast consumption may, however, require other strategies.

Is the process of delivery of an individually tailored lifestyle intervention associated with improvements in LDL cholesterol and multiple lifestyle behaviours in people with familial hypercholesterolemia?

Background

More insight in the association between reach, dose and fidelity of intervention components and effects is needed. In the current study, we aimed to evaluate reach, dose and fidelity of an individually tailored lifestyle intervention in people with Familial Hypercholesterolemia (FH) and the association between intervention dose and changes in LDL-Cholesterol (LDL-C), and multiple lifestyle behaviours at 12-months follow-up.

Methods

Participants (n = 181) randomly allocated to the intervention group received the PRO-FIT intervention consisting of computer-tailored lifestyle advice (PRO-FIT*advice) and counselling (face-to-face and telephone booster calls) using Motivational Interviewing (MI). According to a process evaluation plan, intervention reach, dose delivered and received, and MI fidelity were assessed using the recruitment database, website/counselling logs and the Motivational Interviewing Treatment Integrity (MITI 3.1.1.) code. Regression analyses were conducted to explore differences between participant and non-participant characteristics, and the association between intervention dose and change in LDL-C, and multiple lifestyle behaviours.

Results

A 34% (n = 181) representative proportion of the intended intervention group was reached during the recruitment phase; participants did not differ from non-participants (n = 623) on age, gender and LDL-C levels. Of the participants, 95% received a PRO-FIT*advice log on account, of which 49% actually logged on and completed at least one advice module. Nearly all participants received a face-to-face counselling session and on average, 4.2 telephone booster calls were delivered. None of the face-to-face sessions were implemented according to MI guidelines. Overall, weak non-significant positive associations were found between intervention dose and LDL-C and lifestyle behaviours.

Conclusions

Implementation of the PRO-FIT intervention in practice appears feasible, particularly PRO-FIT*advice, since it can be relative easily implemented with a high dose delivered. However, only less than half of the intervention group received the complete intervention-package as intended. Strategies to let participants optimally engage in using web-based computer-tailored interventions like PRO-FIT*advice are needed. Further, more emphasis should be put on more extensive MI training and monitoring/supervision.

Trial registration

NTR1899 at ww.trialregister.nl.

VIP in construction: systematic development and evaluation of a multifaceted health programme aiming to improve physical activity levels and dietary patterns among construction workers

BACKGROUND

The prevalence of both overweight and musculoskeletal disorders (MSD) in the construction industry is high. Many interventions in the occupational setting aim at the prevention and reduction of these health problems, but it is still unclear how these programmes should be designed. To determine the effectiveness of interventions on these health outcomes randomised controlled trials (RCTs) are needed. The aim of this study is to systematically develop a tailored intervention for prevention and reduction of overweight and MSD among construction workers and to describe the evaluation study regarding its (cost-)effectiveness.

METHODS/DESIGN

The Intervention Mapping (IM) protocol was applied to develop and implement a tailored programme aimed at the prevention and reduction of overweight and MSD. The (cost-) effectiveness of the intervention programme will be evaluated using an RCT. Furthermore, a process evaluation will be conducted. The research population will consist of blue collar workers of a large construction company in the Netherlands.

INTERVENTION

The intervention programme will be aimed at improving (vigorous) physical activity levels and healthy dietary behaviour and will consist of tailored information, face-to-face and telephone counselling, training instruction (a fitness "card" to be used for exercises), and materials designed for the intervention (overview of the company health promoting facilities, waist circumference measuring tape, pedometer, BMI card, calorie guide, recipes, and knowledge test). MAIN STUDY PARAMETERS/ENDPOINTS: The intervention effect on body weight and waist circumference (primary outcome measures), as well as on lifestyle behaviour, MSD, fitness, CVD risk indicators, and work-related outcomes (i.e. productivity, sick leave) (secondary outcome measures) will be assessed.

DISCUSSION

The development of the VIP in construction intervention led to a health programme tailored to the needs of construction workers. This programme, if proven effective, can be directly implemented.

TRIAL REGISTRATION

Netherlands Trial Register (NTR): NTR2095.

A worksite vitality intervention to improve older workers' lifestyle and vitality-related outcomes: results of a randomised controlled trial

Objective

To evaluate the effectiveness of a worksite vitality intervention on vigorous physical activity (VPA), fruit intake, aerobic capacity, mental health and need for recovery after work among older hospital workers (ie, 45 years and older).

Methods

The 6-month intervention was evaluated using a randomised controlled trial design. Workers who were randomised to the intervention group (n=367; control: n=363) received the Vital@Work intervention containing (1) a Vitality Exercise Program (VEP) combined with (2) three visits to Personal Vitality Coach. The VEP consisted of a weekly yoga session, a weekly workout session and weekly unsupervised aerobic exercising. Free fruit was provided at the VEP. Data on the outcome measures were collected (ie, year 2009–2010) at baseline (n=730) and 6 months of follow-up after baseline (n=575) using questionnaires, accelerometers and 2 km walk tests. Effects were analysed according to the intention-to-treat principle with complete cases (n=575) and imputed data (n=730) using linear regression analyses. Additional analyses were performed for high yoga and workout compliance (ie, >mean number of sessions).

Results

Effects were found for sports activities (β=40.4 min/week, 95% CI 13.0 to 67.7) and fruit intake (β=2.7 pieces/week, 95% CI 0.07 to 4.7) and were stronger for workers with high compliance to yoga (sport: β=49.6 min/week, 95% CI 13.9 to 85.2; fruit: β=3.8 pieces/week, 95% CI 1.1 to 6.4) and workout sessions (sport: β=72.9 min/week, 95% CI 36.1 to 109.8; fruit: β=4.0 pieces/week, 95% CI 1.1 to 6.4). The intervention group lowered their need for recovery, when compared to controls (β=−3.5, 95% CI −6.4 to −0.54), with stronger effects for high workout compliance (β=−5.3, 95% CI −9.3 to −1.3). No effects were found on VPA, aerobic capacity or mental health.

Conclusions

Implementation of worksite yoga and workout facilities and minimal fruit interventions should be considered by employers to promote transitions into healthier lifestyles and thereby health.

Evaluation of a short food frequency questionnaire used among Norwegian children

Objective

The aim of this study was to evaluate a short food frequency questionnaire (FFQ) against a four-day precoded food diary (PFD) with regard to frequency of food intake among Norwegian 9- and 13-year-olds.

Subjects and design

A total of 733 9-year-olds and 904 13-year-olds completed first a short FFQ and one to two weeks later a four-day PFD. The short FFQ included questions about 23 food items, including different drinks, fruits, vegetables, bread, fish, pizza, sweets, chocolate and savoury snacks. The PFD covered the whole diet.

Results

When comparing mean intake from the PFD with comparable food items in the FFQ, all food items showed that increasing intake measured with the PFD corresponded with increasing intake with the short FFQ. However, participants reported a significantly higher frequency of intake for most foods with the short FFQ compared with PFD, except for soft drinks with sugar and sweets. The median Spearman correlation coefficient between the two methods was 0.36 among the 9-year-olds and 0.32 among the 13-year-olds. Often eaten foods such as fruits and vegetables had higher correlations than seldom eaten foods such as pizza and potato chips. The median correlation coefficients for drinks alone were higher (r=0.47) for both age groups.

Conclusions

Results indicate that the short FFQ was able to identify high and low consumers of food intake and had a moderate capability to rank individuals according to food intake. Drinks, fruits and vegetables had better correlations with the PFD than infrequently eaten food items.

Appreciation and implementation of the Krachtvoer healthy diet promotion programme for 12- to 14- year-old students of prevocational schools

Background

Krachtvoer is a school-based healthy diet programme, developed in 2001 and revised in 2007 to meet the needs of particular segments of the target population as well as a wider target group. The main aims of the present process evaluation of the revised programme were to examine student and teacher appreciation of the programme, completeness of and adherence to its implementation, and relations between appreciation and completeness of implementation.

Methods

Data were collected among 22 teachers and 1117 students of 13 schools, using student evaluation forms, teacher logbooks, telephone interviews, and classroom observations.

Results

Results indicate favourable levels of teacher and student appreciation for the programme in general and the revised elements. Girls, first-year students and students with more favourable dietary intakes particularly appreciated individual programme elements. Levels of completeness of implementation were high, but several teachers did not adhere to the intended implementation period. Some moderately strong relations were found between teacher appreciation and completeness of implementation scores.

Conclusion

We conclude that the revisions have resulted in a programme that was appreciated well, also by the extended target group, and was implemented with a high degree of completeness. Teacher appreciation proved potentially important for completeness of implementation. We identified several aspects requiring improvement, indicating the importance of continued programme updates and repeated evaluation.

Parental and child fruit consumption in the context of general parenting, parental education and ethnic background

This study examines the association between parental and child fruit consumption in the context of general parenting, parental education and ethnic background. A cross-sectional study was performed among 1762 parent-child dyads. Mean age of the children was 8 years. One parent completed a questionnaire to measure their own and their child's fruit consumption, parenting style, education level and ethnicity. In mediation and moderation analyses, child fruit consumption was regressed on parental fruit consumption, parenting style, parental education and ethnicity. Participating children consumed on average 7.5 pieces of fruit per week. Fourteen percent met the recommended Dutch norm of two pieces of fruit per day. Parental and child fruit consumption were positively associated. The association was more pronounced under higher levels of psychological control and behavioural control, and among ethnic groups. Additionally, parental education and child fruit consumption were positively associated. Parental fruit consumption partially mediated this association. Interventions are needed to increase child fruit consumption. Interventions should focus on increasing parental fruit consumption and positive parental modelling, with particular focus on low-SES families. Additionally, interventions that combine positive modelling with positive general parenting skills (e.g. increasing behavioural control) may be more effective than interventions that focus on parental modelling alone.

Child consumption of fruit and vegetables: the roles of child cognitions and parental feeding practices

OBJECTIVE

To examine the roles of child cognitions and parental feeding practices in explaining child intentions and behaviour regarding fruit and vegetable consumption.

DESIGN

Cross-sectional surveys among pre-adolescent children and their parents.

SETTING

The child questionnaire included measures of fruit and vegetable consumption and cognitions regarding fruit and vegetable consumption as postulated by the Attitude-Social Influence-Self-Efficacy (ASE) model. The parent questionnaire included measures of parental feeding practices derived from the Comprehensive Feeding Practices Questionnaire (CFPQ).

SUBJECTS

In total, 963 parents and 796 students in grades 5 and 6 from eighteen schools in the south-western part of Norway participated.

RESULTS

A large portion of child intention to eat fruit and child fruit consumption was explained by child cognitions (29 % and 25 %, respectively). This also applied to child intention to eat vegetables and child vegetable consumption (42 % and 27 %, respectively). Parent-reported feeding practices added another 3 % to the variance explained for child intention to eat fruit and 4 % to the variance explained for child vegetable consumption.

CONCLUSIONS

The results from the present study supported the application of the ASE model for explaining the variance in child intentions to eat fruit and vegetables and in child consumption of fruit and vegetables. Furthermore, our findings indicated that some parental feeding practices do have an influence on child intentions and behaviour regarding fruit and vegetable consumption. However, the role of parental feeding practices, and the pathways between feeding practices and child eating intentions and behaviour, needs to be further investigated.

Mindful "Vitality in Practice": an intervention to improve the work engagement and energy balance among workers; the development and design of the randomised controlled trial

Background

Modern working life has become more mental and less physical in nature, contributing to impaired mental health and a disturbed energy balance. This may result in mental health problems and overweight. Both are significant threats to the health of workers and thus also a financial burden for society, including employers. Targeting work engagement and energy balance could prevent impaired mental health and overweight, respectively.

Methods/Design

The study population consists of highly educated workers in two Dutch research institutes. The intervention was systematically developed, based on the Intervention Mapping (IM) protocol, involving workers and management in the process. The workers' needs were assessed by combining the results of interviews, focus group discussions and a questionnaire with available literature. Suitable methods and strategies were selected resulting in an intervention including: eight weeks of customized mindfulness training, followed by eight sessions of e-coaching and supporting elements, such as providing fruit and snack vegetables at the workplace, lunch walking routes, and a buddy system. The effects of the intervention will be evaluated in a RCT, with measurements at baseline, six months (T1) and 12 months (T2). In addition, cost-effectiveness and process of the intervention will also be evaluated.

Discussion

At baseline the level of work engagement of the sample was "average". Of the study population, 60.1% did not engage in vigorous physical activity at all. An average working day consists of eight sedentary hours. For the Phase II RCT, there were no significant differences between the intervention and the control group at baseline, except for vigorous physical activity. The baseline characteristics of the study population were congruent with the results of the needs assessment. The IM protocol used for the systematic development of the intervention produced an appropriate intervention to test in the planned RCT.

Trial registration number

Netherlands Trial Register (NTR): NTR2199

Optimizing diffusion of an online computer tailored lifestyle program: a study protocol

Background

Although the Internet is a promising medium to offer lifestyle interventions to large amounts of people at relatively low costs and effort, actual exposure rates of these interventions fail to meet the high expectations. Since public health impact of interventions is determined by intervention efficacy and level of exposure to the intervention, it is imperative to put effort in optimal dissemination. The present project attempts to optimize the dissemination process of a new online computer tailored generic lifestyle program by carefully studying the adoption process and developing a strategy to achieve sustained use of the program.

Methods/Design

A prospective study will be conducted to yield relevant information concerning the adoption process by studying the level of adoption of the program, determinants involved in adoption and characteristics of adopters and non-adopters as well as satisfied and unsatisfied users. Furthermore, a randomized control trial will be conducted to the test the effectiveness of a proactive strategy using periodic e-mail prompts in optimizing sustained use of the new program.

Discussion

Closely mapping the adoption process will gain insight in characteristics of adopters and non-adopters and satisfied and unsatisfied users. This insight can be used to further optimize the program by making it more suitable for a wider range of users, or to develop adjusted interventions to attract subgroups of users that are not reached or satisfied with the initial intervention. Furthermore, by studying the effect of a proactive strategy using period prompts compared to a reactive strategy to stimulate sustained use of the intervention and, possibly, behaviour change, specific recommendations on the use and the application of prompts in online lifestyle interventions can be developed.

Trial registration

Dutch Trial Register NTR1786 and Medical Ethics Committee of Maastricht University and the University Hospital Maastricht (NL2723506809/MEC0903016).

Tailored print communication and telephone motivational interviewing are equally successful in improving multiple lifestyle behaviors in a randomized controlled trial

Background

Computer tailoring and motivational interviewing show promise in promoting lifestyle change, despite few head-to-head comparative studies.

Purpose

Vitalum is a randomized controlled trial in which the efficacy of these methods was compared in changing physical activity and fruit and vegetable consumption in middle-aged Dutch adults.

Methods

Participants (n = 1,629) were recruited via 23 general practices and randomly received either four tailored print letters, four motivational telephone calls, two of each type of intervention, or no information. The primary outcomes were absolute change in self-reported physical activity and fruit and vegetable consumption.

Results

All three intervention groups (i.e., the tailored letters, the motivational calls, and the combined version) were equally and significantly more effective than the control group in increasing physical activity (hours/day), intake of fruit (servings/day), and consumption of vegetables (grams/day) from baseline to the intermediate measurement (week 25), follow-up 1 (week 47) and 2 (week 73). Effect sizes (Cohen’s d) ranged from 0.15 to 0.18. Participants rated the interventions positively; interviews were more positively evaluated than letters.

Conclusions

Tailored print communication and telephone motivational interviewing or their combination are equally successful in changing multiple behaviors.

Electronic supplementary material

The online version of this article (doi:10.1007/s12160-010-9231-3) contains supplementary material, which is available to authorized users.

The Terneuzen Birth Cohort. Longer exclusive breastfeeding duration is associated with leaner body mass and a healthier diet in young adulthood

Background

Breastfeeding (BF) is protective against overweight and is associated with dietary behaviour. The aims of our study were to assess the relationship between exclusive BF duration and BMI, waist circumference (WC) and waist-hip ratio (WHR) at adulthood, and to study whether dietary behaviour could explain the relationship between BF duration and the proxies of fat mass.

Methods

In 2004-2005, 822 subjects from the Terneuzen Birth Cohort (n = 2,604), aged 18-28 years, filled in postal questionnaires including sociodemographic factors and aspects of dietary behaviour (dietary pattern, and consumption of fruit and vegetables, snacks, sweetened beverages and alcohol); 737 subjects also underwent anthropometric measurements of weight, height, and waist and hip circumference. The relationship between exclusive BF duration and dietary outcomes was investigated by logistic regression analysis. The relationships of BF duration with the anthropometric measures were investigated by linear regression analyses. All results were corrected for age, gender and possible confounders. Finally, regression analyses were performed to investigate if diet factors had a mediating effect on the relationship between BF duration and fat mass.

Results

A significant inverse dose-response relationship of BF duration was found for BMI (β-0.13, SE 0.06), WC (β-0.39, SE 0.18) and WHR (β-0.003, SE 0.001), after correction for age, gender and confounders. The odds ratio (OR) of exclusive BF duration in months for a breakfast frequency of at least 5 times a week was 1.16 (95%CI 1.06-1.27), and for snack consumption of less than twice a week was 1.15 (95%CI 1.06-1.25). Both ORs were corrected for age, gender and confounders. For other dietary outcomes, the results point in the same direction, i.e. a positive relationship with BF duration, but these were not statistically significant. A mediating effect of the diet factors on the association between BF and anthropometric outcomes was not shown.

Conclusions

Exclusive BF duration had a significant inverse dose-response relationship with BMI, WC and WHR at young adulthood. BF duration was positively related to a healthier diet at adulthood, but this did not explain the protective effect of BF against body fat. Our results underline the recommendation of the WHO to exclusively breastfeed for 6 months or longer.

Product samples stimulate choice of unfamiliar healthful food products

The purpose of this study was to assess whether the availability of a product sample of an unfamiliar low-fat or fruit and vegetable products stimulates choice for this product among food neophobic young adults. The study had a 2 (experimental vs. control group) by 4 (low-fat bread spread, low-fat cheese, fruit juice, fruit and vegetable juice) between subjects design with a pre-and post-experiment questionnaire. The study was conducted in restaurant rooms of several educational institutions in the Netherlands among a convenience sample of 197 food neophobic young adults aged 17-25 years. A small bite or sip-sized sample of the target product was provided as an intervention. The effect measure was choice of either an unfamiliar healthful food product or a traditional food product. Offering a sample of an unfamiliar healthful food product resulted in 51% of the participants in the experimental group choosing this product vs. 36.4% in the control group. Providing food product samples seems to be a promising strategy in healthy diet promotion programs for food neophobic young adults to increase first-time trial of unfamiliar low-fat and fruit and vegetable products.

Effect evaluation of a Motivational Interviewing based counselling strategy in diabetes care

AIM

The present study assessed the effects of a Motivational Interviewing (MI) based counselling training for nurses on clinical, behavioural and process outcomes among diabetes type 2 patients.

METHODS

The study is an RCT with follow-up measurements after 12 and 24 months. Thirty-three nurses and 584 patients participated. Nurses in the experimental condition received the training; control group nurses were trained after the study. The training consisted of two training sessions, two follow-up meetings, written feedback and three direct feedback sessions. Basic MI-principles and techniques and an MI-based counselling protocol were addressed.

RESULTS

Results indicated disadvantageous effects on fat intake and HDL and advantageous effects on chance locus of control and knowledge. No effects were found on vegetable or fruit intake, physical activity, HbA1c, weight, blood pressure, total cholesterol, LDL, triglycerides, health care climate, quality of life or on self-efficacy.

CONCLUSIONS

As in other MI studies, mixed results were found. It would be premature to recommend dissemination of MI in diabetes care. More studies are needed in real-world settings with health care professionals of the field instead of intensively trained MI interventionists. Knowledge should be gained about adequate training and factors contributing to the implementation of MI in daily practice.

The effects of tailored and threatening nutrition information on message attention. Evidence from an event-related potential study

Recent evidence indicates that attention is higher for individually tailored as compared to non-tailored health communications. The present study examined whether the predicted increased attention for the tailored as opposed to general nutrition education messages is moderated by presenting high vs. low threat information about the negative consequences of an unhealthy diet. In a mixed subject experimental design, undergraduate students (N=34) were reading tailored and non-tailored nutrition education messages with either high or low threat information about the negative consequences of an unhealthy diet. At the same time, they had to pay attention to specific odd auditory stimuli in a sequence of frequent auditory stimuli (oddball paradigm). The amount of attention allocation was measured by recording event-related potentials (ERPs; i.e., N100, MMN, P300) and reaction times. Result revealed main effects of tailoring and threat, indicating that more attention resources were allocated to tailored vs. non-tailored messages and to low threat vs. high threat messages. The findings confirm that tailoring is an effective means to draw attention to health messages, whereas threat information seems to result in a loss in message attention.

Reduction in sugar-sweetened beverages is not associated with more water or diet drinks

OBJECTIVE

The Dutch Obesity Intervention in Teenagers (DOiT) is a school-based randomised controlled trial that was effective in decreasing the consumption of sugar-sweetened beverages among adolescents. The present study examined, using mediation analysis, whether this decrease in consumption of sugar-sweetened beverages could be explained by an increase in the consumption of water or diet drinks.

DESIGN

Participants completed a questionnaire about their beverage consumption at baseline and at 8 months (immediately post-intervention), 12- and 20-month follow-ups. A series of multi-level linear regression analyses were performed to examine water and diet drink consumption as potential mediators of the intervention effect on the consumption of sugar-sweetened beverages.

SETTING

Eighteen Dutch secondary schools.

SUBJECTS

A total of 747 adolescents (mean age: 12·7 years).

RESULTS

In addition to the DoiT intervention effect of a reduction in the consumption of sugar-sweetened beverages at 8 months (-284 ml/d; 95 % CI -420, -148) and 12 months (-260 ml/d; 95 % CI -360, -160), there was also a significant reduction in diet drinks at 8 months (-52 ml/d; 95 % CI -89, -16). There was no significant difference in water consumption at any follow-up. The decrease in sugar-sweetened beverage consumption could not be explained by an increase in water or diet drink consumption at any time point.

CONCLUSIONS

Interventions aimed at reducing sugar-sweetened beverage consumption may be effective without changing consumption of other beverages. Reducing sugar-sweetened beverages was, however, a main message of the DOiT intervention. It is possible that a concomitant promotion of water may have resulted in a greater increase in water intake and replacement of sugar-sweetened beverages with water.

Validation of brief instruments to measure adult fruit and vegetable consumption

Four brief food frequency questionnaires were developed and validated to measure an adult's usual daily intake of fruit or vegetable servings over the past month. Fifty males and 50 females, aged 25-52 years, completed two fruit instruments, two vegetable instruments, and a dietary history (the reference method). Individual agreement and group mean estimation were assessed. The 5-item fruit instrument and the 15-item vegetable instrument performed best. At an individual level, the 5-item fruit instrument had 64% sensitivity and 88% specificity for assessing goal attainment (≥ 2 fruit servings/day), while the 15-item vegetable instrument had 67% sensitivity and 82% specificity for measuring goal attainment (≥ 3 vegetable servings/day). At a group level, the 15-item vegetable instrument closely estimated mean intake (ratio of geometric means=0.94), while the 5-item fruit instrument overestimated mean intake by 32%. Nevertheless, when it was used to rank participants, reference method fruit servings increased across the quartiles of intake. These two instruments can be used to assess goal attainment. This vegetable instrument can also be used to estimate group mean intakes, while the fruit instrument can be used to rank participants. Used appropriately, these instruments can be used for screening, monitoring, and evaluation purposes in New Zealand public health and clinical settings.

Neuroticism, conscientiousness and fruit consumption: exploring mediator and moderator effects in the theory of planned behaviour

Integrating the theory of planned behaviour (TPB) with the five-factor model (FFM) of personality may provide insight into the cognitive and motivational mechanisms linking personality with health behaviour, but this issue has received very little attention regarding fruit consumption. Mediator effects of TPB concepts in the personality-fruit consumption link, as well as moderator effects of personality in the intention-fruit consumption link, were therefore investigated in the present study. Data on fruit consumption, TPB concepts and FFM dimensions were gathered among 405 respondents in face-to-face interviews using questionnaires. Structural equation modelling was used to investigate the mediator and moderator effects. The direct effect of conscientiousness on fruit consumption was mediated by attitude and perceived behavioural control, while no direct effect of neuroticism on fruit consumption was found. Neuroticism moderated the intention-fruit consumption relationship with the weakest relationship for those scoring high on neuroticism. Conscientiousness did not moderate the intention-fruit consumption relationship. TPB variables are mediators in the conscientiousness-fruit consumption link. Whether fruit consumption is intentional may be dependent upon the personality dimension neuroticism. Personality dimensions may be a useful addition to the TPB and should be considered in health behaviour change interventions.

Family environmental factors do not explain differences in the behavioral effect of a healthy diet promotion program in lower vocational schools among 12- to 14-year-old adolescents

PURPOSE

Assess whether family environmental factors affected changes in fruit and snack consumption among 12- to 14-year-old adolescents participating in a Dutch healthy diet promotion program.

DESIGN

Data were derived from pretest and posttest questionnaires completed by adolescents in 10 schools in the intervention arm of the program trial and questionnaires completed by their parents during program implementation.

SETTING

Lower vocational schools in the southern and central parts of The Netherlands.

SUBJECTS

Questionnaire answers of 502 parents were matched with those of their children.

INTERVENTION

Eight school lessons using various theory-based materials and strategies.

MEASURES

Dietary intake, ethnicity, education level, employment status, parenting style, food purchase considerations, family food rules, and food availability and accessibility at home.

ANALYSIS

Regression analyses.

RESULTS

No significant family environmental predictors of program-induced changes in either fruit or snack intake were found.

CONCLUSION

A limitation of the study was that all data were self-reported. No evidence was found that there were subgroups of adolescents who profited less from the program because of family environmental factors.

A tailored lifestyle intervention to reduce the cardiovascular disease risk of individuals with Familial Hypercholesterolemia (FH): design of the PRO-FIT randomised controlled trial

Background

Because of a high cardiovascular disease (CVD) risk in people with Familial Hypercholesterolemia (FH), early prevention of cardiovascular disease is important for health gain and cost reduction. This project focuses on the development and evaluation of an innovative intervention aiming to reduce CVD risk by promoting a healthy lifestyle among people with FH.

Methods

This project is designed as a randomised controlled trial in which individuals with FH will be assigned randomly to a control or intervention group. In the intervention group (n = 200), participants will receive a personalized intervention which is a combination of web-based tailored lifestyle advice and personal counselling by a lifestyle coach. The control group (n = 200) will receive care as usual. Primary outcomes are biological indicators of CVD risk: systolic blood pressure, glucose, BMI, waist circumference and lipids (triglycerides, total, LDL and HDL cholesterol). Secondary outcomes are: healthy lifestyle behaviour (with regard to smoking, physical activity, dietary pattern and compliance to statin therapy) and psychological correlates and determinants of healthy lifestyle behaviour (knowledge, attitude, risk perception, social influence, self-efficacy, cues to action, intention and autonomy). Measurement will take place at baseline, and at 3 and 12 months after randomisation. Additionally, a throughout process-evaluation will be conducted to assess and monitor intervention implementation during the trial.

Discussion

Results of the PRO-FIT project will provide information about the effects and implementation of a healthy lifestyle intervention for individuals with FH. Our experiences with this intervention will be indicative about the suitability, feasibility and benefits of this approach for future interventions in other high-risk groups, such as Familial Combined Hypercholesterolemia (FCH) and diabetes.

Trial registration number

NTR1899

Cognitive and home environmental predictors of change in sugar-sweetened beverage consumption among adolescents

Sugar-sweetened beverage (SSB) consumption may increase risk for unnecessary weight gain. To develop interventions discouraging consumption, more insight is needed about cognitive and environmental predictors related to the decrease in SSB consumption. The present paper aims (1) to describe the relationship between potential cognitive determinants of change (attitudes, subjective norms, perceived behavioural control and intentions) and perceived environmental factors (family food rule and home availability of SSB) with changes in SSB consumption between baseline and 4-month follow-up and (2) to study whether the relationships between the environmental factors and SSB consumption are mediated by the cognitive determinants. Information on possible predictors and SSB intake at baseline and 4-month follow-up was provided by 348 Dutch adolescents (aged 12–13 years) through online questionnaires that were completed at school. Multilevel logistic regression and mediation analyses were used to determine direct and indirect associations between predictors and behaviour. The present results show that a high perceived behavioural control to decrease intake at baseline was associated with a decrease in consumption of SSB between baseline and follow-up (OR = 0·53). Low availability and a stricter family food rule were associated with a decrease in SSB consumption between baseline and follow-up (OR = 2·39, 0·54). The association between availability and decrease in SSB consumption was for 68 % mediated by perceived behavioural control to drink less. In conclusion, interventions to decrease SSB intake should focus on improving attitudes and perceived behavioural control to reduce intake, and on limiting home availability and stimulating stricter family food rules regarding SSB consumption.

Design of the Balance@Work project: systematic development, evaluation and implementation of an occupational health guideline aimed at the prevention of weight gain among employees

Background

Occupational health professionals may play an important role in preventive health promotion activities for employees. However, due to a lack of knowledge and evidence- and practice based methods and strategies, interventions are hardly being implemented by occupational physicians to date. The aim of the Balance@Work project is to develop, evaluate, and implement an occupational health guideline aimed at the prevention of weight gain among employees.

Methods

Following the guideline development protocol of the Netherlands Society of Occupational Medicine and the Intervention Mapping protocol, the guideline was developed based on literature, interviews with relevant stakeholders, and consensus among an expert group. The guideline consists of an individual and an environmental component. The individual component includes recommendations for occupational physicians on how to promote physical activity and healthy dietary behavior based on principles of motivational interviewing. The environmental component contains an obesogenic environment assessment tool. The guideline is evaluated in a randomised controlled trial among 20 occupational physicians. Occupational physicians in the intervention group apply the guideline to eligible workers during 6 months. Occupational physicians in the control group provide care as usual. Measurements take place at baseline and 6, 12, and 18 months thereafter. Primary outcome measures include waist circumference, daily physical activity and dietary behavior. Secondary outcome measures include sedentary behavior, determinants of behavior change, body weight and body mass index, cardiovascular disease risk profile, and quality of life. Additionally, productivity, absenteeism, and cost-effectiveness are assessed.

Discussion

Improving workers' daily physical activity and dietary behavior may prevent weight gain and subsequently improve workers' health, increase productivity, and reduce absenteeism. After an effect- and process evaluation the guideline will be adjusted and, after authorisation, published. Together with several implementation aids, the published guideline will be disseminated broadly by the Netherlands Society of Occupational Medicine.

Trial Registration

ISRCTN73545254/NTR1190

Involving patients in cardiovascular risk management with nurse-led clinics: a cluster randomized controlled trial

BACKGROUND

Preventive guidelines on cardiovascular risk management recommend lifestyle changes. Support for lifestyle changes may be a useful task for practice nurses, but the effect of such interventions in primary prevention is not clear. We examined the effect of involving patients in nurse-led cardiovascular risk management on lifestyle adherence and cardiovascular risk.

METHODS

We performed a cluster randomized controlled trial in 25 practices that included 615 patients. The intervention consisted of nurse-led cardiovascular risk management, including risk assessment, risk communication, a decision aid and adapted motivational interviewing. The control group received a minimal nurse-led intervention. The self-reported outcome measures at one year were smoking, alcohol use, diet and physical activity. Nurses assessed 10-year cardiovascular mortality risk after one year.

RESULTS

There were no significant differences between the intervention groups. The effect of the intervention on the consumption of vegetables and physical activity was small, and some differences were only significant for subgroups. The effects of the intervention on the intake of fat, fruit and alcohol and smoking were not significant. We found no effect between the groups for cardiovascular 10-year risk.

INTERPRETATION

Nurse-led risk communication, use of a decision aid and adapted motivational interviewing did not lead to relevant differences between the groups in terms of lifestyle changes or cardiovascular risk, despite significant within-group differences.

Parenting styles, family structure and adolescent dietary behaviour

Objective

To examine associations between parenting styles, family structure and aspects of adolescent dietary behaviour.

Design

Cross-sectional study.

Setting

Secondary schools in the East Midlands, UK.

Subjects

Adolescents aged 12–16 years (n 328, 57 % boys) completed an FFQ assessing their consumption of fruit, vegetables, unhealthy snacks and breakfast. Adolescents provided information on parental and sibling status and completed a seventeen-item instrument measuring the general parenting style dimensions of involvement and strictness, from which four styles were derived: indulgent, neglectful, authoritarian, authoritative.

Results

After controlling for adolescent gender and age, analysis of covariance revealed no significant interactions between parenting style and family structure variables for any of the dietary behaviours assessed. Significant main effects for family structure were observed only for breakfast consumption, with adolescents from dual-parent families (P < 0·01) and those with no brothers (P < 0·05) eating breakfast on more days per week than those from single-parent families and those with one or more brother, respectively. Significant main effects for parenting style were observed for all dietary behaviours apart from vegetable consumption. Adolescents who described their parents as authoritative ate more fruit per day, fewer unhealthy snacks per day, and ate breakfast on more days per week than those who described their parents as neglectful.

Conclusions

The positive associations between authoritative parenting style and adolescent dietary behaviour transcend family structure. Future research should be food-specific and assess the efficacy of strategies promoting the central attributes of an authoritative parenting style on the dietary behaviours of adolescents from a variety of family structures.

The Vital@Work Study. The systematic development of a lifestyle intervention to improve older workers' vitality and the design of a randomised controlled trial evaluating this intervention

Background

A major contributor of early exit from work is a decline in health with increasing age. As healthy lifestyle choices contribute to better health outcomes, an intervention aimed at an improved lifestyle is considered a potentially effective tool to keep older workers healthy and vital, and thereby to prolong labour participation.

Methods

Using the Intervention Mapping (IM) protocol, a lifestyle intervention was developed based on information obtained from 1) literature, 2) a short lifestyle questionnaire aimed at indentifying the lifestyle behaviours among the target group, and 3) focusgroup (FG) interviews among 36 older workers (aged 45⁺ years) aimed at identifying: a) key determinants of lifestyle behaviour, b) a definition of vitality, and c) ideas about how vitality can be improved by lifestyle.

The main lifestyle problems identified were: insufficient levels of physical activity and insufficient intake of fruit and vegetables. Using information from both literature and FG interviews, vitality consists of a mental and a physical component. The interviewees suggested to improve the mental component of vitality by means of relaxation exercises (e.g. yoga); physical vitality could be improved by aerobic endurance exercise and strength training.

The lifestyle intervention (6 months) consists of three visits to a Personal Vitality Coach (PVC) combined with a Vitality Exercise Programme (VEP). The VEP consists of: 1) once a week a guided yoga group session aimed at relaxation exercises, 2) once a week a guided aerobic workout group session aimed at improving aerobic fitness and increasing muscle strength, and 3) older workers will be asked to perform once a week for at least 45 minutes vigorous physical activity without face-to-face instructions (e.g. fitness). Moreover, free fruit will be offered at the group sessions of the VEP. The lifestyle intervention will be evaluated in a RCT among older workers of two major academic hospitals in the Netherlands. At baseline, after 6 and 12 months, measurements (primary: lifestyle and vitality, and secondary: work-engagement and productivity) will take place.

Discussion

The lifestyle programme is developed specifically tailored to the needs of the older workers and which is aimed at improving their vitality.

Trial registration

NTR1240

Patterns of adolescent physical activity and dietary behaviours

Background

The potential synergistic effects of multiple dietary and physical activity behaviours on the risk of chronic conditions and health outcomes is a key issue for public health. This study examined the prevalence and clustering patterns of multiple health behaviours among a sample of adolescents in the UK.

Methods

Cross-sectional survey of 176 adolescents aged 12–16 years (49% boys). Adolescents wore accelerometers for seven days and completed a questionnaire assessing fruit, vegetable, and breakfast consumption. The prevalence of adolescents meeting the physical activity (≥ 60 minutes moderate-to-vigorous physical activity/day), fruit and vegetable (≥ 5 portions of FV per day) and breakfast recommendations (eating breakfast on ≥ 5 days per week), and clustering patterns of these health behaviours are described.

Results

Boys were more active than girls (p < 0.001) and younger adolescents were more active than older adolescents (p < 0.01). Boys ate breakfast on more days per week than girls (p < 0.01) and older adolescents ate more fruit and vegetables than younger adolescents (p < 0.01). Almost 54% of adolescents had multiple risk behaviours and only 6% achieved all three of the recommendations. Girls had significantly more risk factors than boys (p < 0.01). For adolescents with two risk behaviours, the most prevalent cluster was formed by not meeting the physical activity and fruit and vegetable recommendations.

Conclusion

Many adolescents fail to meet multiple diet and physical activity recommendations, highlighting that physical activity and dietary behaviours do not occur in isolation. Future research should investigate how best to achieve multiple health behaviour change in adolescent boys and girls.

Single-item and multiple-item measures of adherence to public health behavior guidelines were incongruent

OBJECTIVE

Physical activity (PA) and fruit and vegetable consumption may prevent or delay the development of hypertension and cardiovascular diseases. We examined adherence rates to single and combinations of Dutch public health guidelines for these behaviors by comparing and combining two self-report measurements.

STUDY DESIGN AND SETTING

The behaviors of 2,568 Dutch participants aged 45-70 years were measured using one item and multiple items. Patients were classified as meeting or not meeting a guideline using both measurements separately and combined.

RESULTS

Substantially more participants met guidelines when measured with multiple items than when measured with one item, with differences of 21-39%. Combined measurements resulted in fewer participants meeting guidelines than multiple-item measurements used alone. Combined measurements showed that 17%, 12%, and 34% of participants met the guidelines for fruit and vegetable consumption and PA, respectively; only 3% met all three guidelines. Sociodemographic variables explained less than 4% of the variance of congruency between single- and multiple-item measurements.

CONCLUSION

When assessing adherence rates, the level appears dependent on the method of self-report chosen. Hence, more research must analyze which adherence measurement will result in valid responses and which variables are associated with congruency between single- and multiple-item measurements.

Ethnic differences in BMI among Dutch adolescents: what is the role of screen-viewing, active commuting to school, and consumption of soft drinks and high-caloric snacks?

BACKGROUND

The threats posed by the rising prevalence of overweight and obesity on public health have been widely acknowledged. Several population groups, which deserve special attention because of their higher prevalence rates, have been identified. These include adolescents and ethnic sub-groups. The aim of the present study was twofold: (1) to assess ethnic differences in body mass index (BMI) and in behaviours that are related to both energy intake and energy expenditure, and (2) to examine whether these behaviours explain the relationship between ethnicity and BMI.

METHODS

We conducted a cross-sectional data analysis among 957 Dutch adolescents (mean age = 12.7 years). Body height and weight were measured using a standardized protocol. Adolescents completed a questionnaire on screen-viewing behaviour, physical activity, consumption of sugar-containing beverages, and consumption of high-caloric snacks.

RESULTS

In our study sample 121 adolescents (= 13%) were of Non-Western origin. BMI was significantly higher in Non-Western adolescents (boys: 19.9 kg/m2, SD = 3.0, girls: 20.9 kg/m2, SD = 3.8) compared to Dutch adolescents (boys: 18.4 kg/m2, SD = 2.8, girls: 19.0 kg/m2, SD = 3.0). Our results show that time spent on television viewing, active commuting to school, and consumption of fruit juices partially mediated the association between BMI and ethnicity.

CONCLUSION

Behaviours related to both energy expenditure and energy intake may contribute to the ethnic differences in BMI in adolescents and should be considered when tailoring overweight prevention programs to ethnic subpopulations.

TRIAL REGISTRATION

International Standard Randomised Controlled Trial Number ISRCTN87127361.

Associations between General Parenting Styles and Specific Food-Related Parenting Practices and Children's Food Consumption

Purpose.

Explore the impact of general parenting style and specific food-related parenting practices on children's dietary habits.

Design.

Cross-sectional study of sixth graders and their parents.

Setting.

Data were gathered (in 2003) in 69 of 100 randomly selected elementary schools in Belgium.

Subjects.

All sixth graders (N = 1957) were invited to participate; 82.4% of their parents gave consent and completed questionnaires, resulting in 1614 parent-child pairs.

Measures.

Children's consumption of breakfast, fruit, vegetables, soft drinks, and sweets was assessed by self-administered food frequency questionnaires. Parents completed questionnaires on sociodemographic characteristics, general parenting styles (authoritarian, authoritative, indulgent, or neglecting) and specific food-related parenting practices (pressure, reward, encouragement through negotiation, catering on children's demands, permissiveness, avoiding negative modeling, and praise).

Analysis.

Logistic regression analyses were performed, with general parenting style and specific food-related parenting practices as predictors and dietary habits as dependent variables, controlling for sociodemographic characteristics and children's weight status.

Results.

General parenting style did not show any significant impact on dietary habits. In contrast, the food-related parenting practice “encouragement through negotiation” showed a significant positive impact, whereas “pressure,” “catering on demand,” and “permissiveness” were practices with an unhealthy impact.

Conclusion.

Nutrition education programs that guide parents in firm but not coercive food parenting skills are likely to have a positive impact upon children's dietary habits.

Phone and e-mail counselling are effective for weight management in an overweight working population: a randomized controlled trial

Background

The work setting provides an opportunity to introduce overweight (i.e., Body Mass Index ≥ 25 kg/m²) adults to a weight management programme, but new approaches are needed in this setting. The main purpose of this study was to investigate the effectiveness of lifestyle counselling by phone or e-mail on body weight, in an overweight working population. Secondary purposes were to establish effects on waist circumference and lifestyle behaviours, and to assess which communication method is the most effective.

Methods

A randomized controlled trial with three treatments: intervention materials with phone counselling (phone group); a web-based intervention with e-mail counselling (internet group); and usual care, i.e. lifestyle brochures (control group). The interventions used lifestyle modification and lasted a maximum of six months. Subjects were 1386 employees, recruited from seven companies (67% male; mean age 43 (SD 8.6) y; mean BMI 29.6 (SD 3.5) kg/m²). Body weight was measured by research personnel and by questionnaire. Secondary outcomes fat, fruit and vegetable intake, physical activity and waist circumference were assessed by questionnaire. Measurements were done at baseline and after six months. Missing body weight was multiply imputed.

Results

Body weight reduced 1.5 kg (95% CI -2.2;-0.8, p < 0.001) in the phone group and 0.6 kg (95% CI -1.3; -0.01, p = 0.045) in the internet group, compared with controls. In completers analyses, weight and waist circumference in the phone group were reduced with 1.6 kg (95% CI -2.2;-1.0, p < 0.001) and 1.9 cm (95% CI -2.7;-1.0, p < 0.001) respectively, fat intake decreased with 1 fatpoint (1 to 4 grams)/day (95% CI -1.7;-0.2, p = 0.01) and physical activity increased with 866 METminutes/week (95% CI 203;1530, p = 0.01), compared with controls. The internet intervention resulted in a weight loss of 1.1 kg (95% CI -1.7;-0.5, p < 0.001) and a reduction in waist circumference of 1.2 cm (95% CI -2.1;-0.4, p = 0.01), in comparison with usual care. The phone group appeared to have more and larger changes than the internet group, but comparisons revealed no significant differences.

Conclusion

Lifestyle counselling by phone and e-mail is effective for weight management in overweight employees and shows potential for use in the work setting.

Trial registration

ISCRTN04265725.

Go4it; study design of a randomised controlled trial and economic evaluation of a multidisciplinary group intervention for obese adolescents for prevention of diabetes mellitus type 2

BACKGROUND

In the Netherlands, the first adolescents with diabetes mellitus type 2 as a result of obesity have recently been diagnosed. Therefore, it is very important that programs aiming at the prevention of type 2 diabetes of obese adolescents are developed and evaluated.

METHODS

Go4it is a multidisciplinary group treatment that focuses on: 1) increasing awareness of the current dietary and physical activity behaviour (i.e. energy balance behaviour), 2) improving diet, 3) decreasing sedentary behaviour, 4) increasing levels of physical activity, and 5) coping with difficult situations. Go4it consists of 7 sessions with an interval of 2-3 weeks.The effectiveness of the multidisciplinary group treatment compared with usual care (i.e. referral to a dietician) was evaluated in a randomised controlled trial. We examined effects on BMI(sds), body composition, energy expenditure, glucose tolerance and insulin resistance (primary outcome measure), as well as dietary and physical activity behaviour and quality of life. An economic evaluation from a societal perspective was conducted alongside the randomised trial to evaluate the cost-effectiveness of the multidisciplinary treatment program vs. usual care.

DISCUSSION

In this paper we described a multidisciplinary treatment program (Go4it) for obese adolescents and the design of a randomised controlled trial and economic evaluation to evaluate its effectiveness and cost-effectiveness.

TRIAL REGISTRATION

Netherlands Trial Register (ISRCTN27626398).

Why did soft drink consumption decrease but screen time not? Mediating mechanisms in a school-based obesity prevention program

OBJECTIVES

This paper aims to identify the mediating mechanisms of a school-based obesity prevention program (DOiT).

METHODS

The DOiT-program was implemented in Dutch prevocational secondary schools and evaluated using a controlled, cluster-randomised trial (September 2003 to May 2004). We examined mediators of effects regarding (1) consumption of sugar containing beverages (SCB); (2) consumption of high caloric snacks; (3) screen-viewing behaviour; and (4) active commuting to school. To improve these behaviours the DOiT-program tried to influence the following potentially mediating variables: attitude, subjective norm, perceived behavioural control, and habit-strength.

RESULTS

Both in boys (n = 418) and girls (n = 436) the DOiT-intervention reduced SCB consumption (between group difference in boys = -303.5 ml/day, 95% CI: -502.4;-104.5, between group difference in girls = -222.3 ml/day, 95% CI: -371.3;-73.2). The intervention did not affect the other examined behaviours. In girls, no intervention effect on hypothetical mediators was found nor evidence of any mediating mechanisms. Boys in intervention schools improved their attitude towards decreasing SCB consumption, while this behaviour became less of a habit. Indeed, attitude and habit strength were significant mediators of the DOiT-intervention's effect (4.5 and 3.8%, respectively) on SCB consumption among boys.

CONCLUSION

Our findings imply that interventions aimed at EBRB-change should be gender-specific. Future studies aimed at reducing SCB consumption among boys should target attitude and habit strength as mediating mechanisms. Our study did not resolve the mediating mechanisms in girls.

TRIAL REGISTRATION

International Standard Randomised Controlled Trial Number Register ISRCTN87127361.

Effects of tailored feedback on multiple health behaviors

BACKGROUND

The effects of tailored intervention on multiple behaviors and possible moderators of tailoring effects have not yet been sufficiently demonstrated.

PURPOSE

The purpose of this study was to examine the effectiveness of a computer-tailored intervention on smoking; physical activity; and fruit, vegetable, and fat intake; and to test potential moderators of the effectiveness (BMI, age, SES, gender, motivation, and the number of behaviors for which respondents met the recommendations from national guidelines).

METHODS

Respondents were randomly assigned to a tailored intervention group, receiving one tailored letter on all of these behaviors, or a control intervention group, receiving one general information letter on all behaviors.

RESULTS

Three months after the baseline assessment, the tailored intervention group showed significantly better effects than the control group for all behaviors studied, except for smoking. Notably, the intervention did not enhance the health behaviors, but rather reduced a decline in these behaviors during the 3-month study interval. Effect sizes were small. No moderating factors were found, except for the number of behaviors for which recommendations were met in the tailoring intervention group on fruit consumption. The largest effects of the tailored intervention were found for fruit in respondents who did not meet the recommendations for any behavior (Cohen's d = 0.3).

CONCLUSIONS

A tailored intervention on multiple behaviors had significant, but limited effects when compared to generic information. The number of bad habits influenced the effects of the tailored intervention on fruit consumption.

Vitalum study design: RCT evaluating the efficacy of tailored print communication and telephone motivational interviewing on multiple health behaviors

Background

A large proportion of adults fail to meet public health guidelines for physical activity as well as fruit, vegetable and fat intake. Interventions are needed to improve these health behaviors. Both computer tailoring and motivational interviewing have shown themselves to be promising techniques for health behavior change. The Vitalum project aims to compare the efficacy of these techniques in improving the health behaviors of adults aged 45–70. This paper describes the design of the Vitalum study.

Methods/Design

Dutch general medical practices (N = 23) were recruited via a registration network or by personal invitation. The participants were then enrolled through these general practices using an invitational letter. They (n = 2,881) received a written baseline questionnaire to assess health behaviors, and potential psychosocial and socio-demographic behavioral determinants. A power analysis indicated that 1,600 participants who were failing to meet the guidelines for physical activity and either fruit or vegetable consumption were needed. Eligible participants were stratified based on hypertension status and randomized into one of four intervention groups: tailored print communication, telephone motivational interviewing, combined, and control. The first two groups either received four letters or took part in four interviews, whereas the combined group received two letters and took part in two interviews in turns at 5, 13, 30 and 43 weeks after returning the baseline questionnaire. Each letter and interview focused on physical activity or nutrition behavior. The participants also took part in a telephone survey 25 weeks after baseline to gather new information for tailoring. There were two follow-up questionnaires, at 47 and 73 weeks after baseline, to measure short- and long-term effects. The control group received a tailored letter after the last posttest. The process, efficacy and cost-effectiveness of the interventions will be examined by means of multilevel mixed regression, cost-effectiveness analyses and process evaluation.

Discussion

The Vitalum study simultaneously evaluates the efficacy of tailored print communication and telephone motivational interviewing, and their combined use for multiple behaviors and people with different motivational stages and education levels. The results can be used by policymakers to contribute to evidence-based prevention of chronic diseases.

Trial Registration

Dutch Trial Register NTR1068

Predictors of stage transitions in the precaution adoption process model

PURPOSE

To explore psychosocial correlates and predictors of stage transitions in the precaution adoption process model (PAPM) for fruit intake.

DESIGN

A cohort completed three electronic questionnaires, at baseline (time 0), 35 days later (time 1), and another 32 days later (time 2).

SETTING

Secured Internet Web site.

SUBJECTS

A cohort of 735 adults was formed from a random sample of an existing Internet panel. The mean age was 37.5 years, 51% were women, and 90% were of Dutch origin. Most respondents (48%) had a medium level of education.

MEASURES

Precaution adoption process model stage, risk perception, perception of own fruit intake level, attitude, pros, cons, subjective norms, social support, modeling, self-efficacy, and fruit intake (assessed using a food frequency questionnaire).

ANALYSIS

Cross-sectional differences in psychosocial variables and fruit intake across PAPM stages at baseline were analyzed using analysis of variance with Tukey multiple comparisons tests. Predictors of PAPM stage transitions between time 0 and time 1 and between time 1 and time 2 were analyzed using logistic regression analysis.

RESULTS

Factors related to attitude and social influences may be important if one is to decide to act, whereas strong self-efficacy may also be required for acting on the decision to act.

CONCLUSION

Although the results should be replicated in a larger and more representative sample, the PAPM seems a good framework for studying fruit intake.