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

BACKGROUND: Large proportions of children do not fulfil the World Health Organization recommendation of eating at least 400 grams of fruit and vegetables (FV) per day. To promote an increased FV intake among children it is important to identify factors which influence their consumption. Both qualitative and quantitative studies are needed. Earlier reviews have analysed evidence from quantitative studies. The aim of this paper is to present a systematic review of qualitative studies of determinants of children's FV intake. METHODS: Relevant studies were identified by searching Anthropology Plus, Cinahl, CSA illumine, Embase, International Bibliography of the Social Sciences, Medline, PsycINFO, and Web of Science using combinations of synonyms for FV intake, children/adolescents and qualitative methods as search terms. The literature search was completed by December 1st 2010. Papers were included if they applied qualitative methods to investigate 6-18-year-olds' perceptions of factors influencing their FV consumption. Quantitative studies, review studies, studies reported in other languages than English, and non-peer reviewed or unpublished manuscripts were excluded. The papers were reviewed systematically using standardised templates for summary of papers, quality assessment, and synthesis of findings across papers. RESULTS: The review included 31 studies, mostly based on US populations and focus group discussions. The synthesis identified the following potential determinants for FV intake which supplement the quantitative knowledge base: Time costs; lack of taste guarantee; satiety value; appropriate time/occasions/settings for eating FV; sensory and physical aspects; variety, visibility, methods of preparation; access to unhealthy food; the symbolic value of food for image, gender identity and social interaction with peers; short term outcome expectancies. CONCLUSIONS: The review highlights numerous potential determinants which have not been investigated thoroughly in quantitative studies. Future large scale quantitative studies should attempt to quantify the importance of these factors. Further, mechanisms behind gender, age and socioeconomic differences in FV consumption are proposed which should be tested quantitatively in order to better tailor interventions to vulnerable groups. Finally, the review provides input to the conceptualisation and measurements of concepts (i.e. peer influence, availability in schools) which may refine survey instruments and theoretical frameworks concerning eating behaviours.

Availability of data assessing the prevalence and trends of overweight and obesity among European adolescents.

OBJECTIVE: To review recent data on objectively measured overweight/obesity in national representative samples of European adolescents (aged 10-18 years), as well as availability of studies assessing trends in overweight/obesity in this target group. Attention was paid to the ability of the data to describe the obesity epidemic, especially in sociodemographic subgroups. DESIGN/SETTING/SUBJECTS: Data on prevalence and trends in overweight/obesity among adolescents in the twenty-seven European Community member states, Iceland, Norway and Switzerland, available as scientific publications as well as reports or unpublished data by the end of 2009, were retrieved. Reports on the most recent objectively measured data from national representative samples were selected and described with regard to the years of data collection, sample sizes, response rates, age ranges included, trends by age, type of measures of overweight/obesity, sociodemographic variables and the sources of information. RESULTS: Objectively measured data on national representative samples were identified for only half of the countries, and the trend studies were mainly conducted applying subnational samples. Most studies used the criteria from the International Obesity Task Force (IOTF) to define overweight/obesity, but the age ranges studied and the years of data collection varied, and information on sample sizes and response rates were often not presented. Data on trends of overweight/obesity over time are increasing, and the most recent studies indicate that the prevalence rate of overweight/obesity has stabilized. Few studies reported data by sociodemographic subgroups other than gender and age. CONCLUSIONS: Objectively measured data on national representative samples of adolescents appear scattered, and there is a large heterogeneity with respect to the quality and comparability of available data. Increasing use of the IOTF criteria for overweight/obesity contributes to improved comparability across studies. Data by sociodemographic subgroups, and in particular by socio-economic status, are scarce.

Associations between diet and (in)activity behaviours with overweight and obesity among 10-18-year-old Czech Republic adolescents.

OBJECTIVES: To assess the prevalence of normal weight, overweight and obesity among 10-18-year-old Czech Republic adolescents and to assess the association between energy balance-related behaviours and overweight/obesity. DESIGN: Cross-sectional data from 'The 6th Nation-wide Anthropological Survey of Children and Adolescents 2001 Czech Republic' have been used. SETTING: Height and weight were objectively measured. Data on adolescents' behaviours were assessed with self-reported questionnaires. Background variables were assessed by means of a parental questionnaire. Multi-level logistic regression analyses were conducted to assess behavioural risk factors of being overweight/obese. SUBJECTS: Data on 31,228 adolescents aged 10-18 years were included in the present study. RESULTS: The highest prevalence of being overweight or obese was found among boys and younger adolescents. Boys were more physically active, watched more television (TV) and used the computer more often than did girls. Being on a diet and skipping meals were positively associated with being overweight/obese, independent of gender. In boys (10-14 years old), inverse associations with being overweight/obese were found when being more physically active. Monitoring weight showed inverse relations with being overweight/obese in 15-18-year-old girls. Watching TV more than 7 h a week was positively associated with being overweight/obese in 15-18-year-old girls, and was found to be negatively associated in boys of the same age group. CONCLUSIONS: These behaviours should be targeted when preventing overweight and obesity among Czech Republic adolescents. Studies using better measures of energy balance-related behaviours are needed.

Longitudinal associations of energy balance-related behaviours and cross-sectional associations of clusters and body mass index in Norwegian adolescents.

BACKGROUND: Insight into the role of energy balance-related behaviours (EBRB) is of great importance when it comes to prevention of weight gain and design of interventions tailored to target these behaviours. OBJECTIVES: First, the present study examines the longitudinal association of four EBRB in Norwegian adolescents. Second, it aims to examine whether clusters of EBRB are cross-sectionally associated with being overweight. DESIGN: The present study is part of the 'Fruits and Vegetables Make the Marks' project. The study sample consists of twenty control schools in two Norwegian counties. METHODS: Survey questionnaires were completed by 884 pupils with an average age at baseline, September 2001, of 11·8 years. In the follow-up surveys in May 2002 and May 2005, a total of 809 and 724 adolescents participated, respectively. Four EBRB were measured: habitual fruit and vegetable intake, snacking and soda consumption, television and computer use and physical activity. RESULTS: Results of the associations between EBRB were similar for boys and girls. The odds, ranging from 1·14 to 12·06, were mostly significant. One out of four clusters, the unhealthy cluster, was significantly and cross-sectionally associated with overweight and obesity. CONCLUSIONS: Longitudinal associations of EBRB show that it is important to start early with interventions that aim to prevent unhealthy behaviours becoming habitual. These behaviours should be targeted at the same time as they tend to co-occur. More research, preferably longitudinal and more objective, is needed to investigate associations between health behaviours and body weight among adolescents.

Direct and indirect association between environmental factors and fruit intake, mediation by psychosocial factors: the Pro Children study.

OBJECTIVES: To explore direct associations between home and school availability of fruit and fruit intake, and the mediating role of attitude towards fruit, liking, perceived barriers and self-efficacy. DESIGN: Cross-sectional study. SETTING: Primary schools in nine European countries. SUBJECTS: Within the Pro Children study, data were collected on perceived home and school availability of fruit, psychosocial factors related to fruit intake and its frequency among 13 305 11-year-old schoolchildren. RESULTS: Significant overall associations were found between child-reported home availability of fruit and fruit intake in all countries and in the total sample. School availability of fruit was associated with fruit intake in the pooled sample and in country-specific analyses in Sweden and the Netherlands. Liking (13·2-49·4 %) and self-efficacy (14·0-25·1 %) were the strongest mediators in the home availability-fruit intake relationship, but there was also a direct association between home availability and fruit intake, except in Spain and the Netherlands. Mediating pathways of the school availability-fruit intake relationship could only be assessed for Norway, Sweden and the total sample. Attitude was a significant mediator in Norway (80·4 %) and in Sweden (25·3 %), while in the total sample also liking (38·7 %) and self-efficacy (23·0 %) were identified as significant mediators. CONCLUSIONS: The association between home availability of fruit and fruit intake is at least partly mediated by personal factors such as liking and self-efficacy indicates that fruit intake is not a complete automatic or unconscious behaviour.

Mothers' involvement in a school-based fruit and vegetable promotion intervention is associated with increased fruit and vegetable intakes--the Pro Children study.

BACKGROUND: Several school-based fruit and vegetable interventions include activities to involve parents, but not much is know about the effectiveness of such a family component on child and parent intake levels. The current study evaluated the effects of the multi-component school-based intervention, 'the Pro Children Study', on mothers' intake levels. Furthermore, associations between level of involvement in the project and improvement in the mothers' intake levels were assessed. METHODS: Effect was evaluated in a cluster randomized controlled trial in Spain, Norway and the Netherlands among mothers of 11-year-olds. Of the 1253 mothers with complete data at baseline, 754 and 476 had complete data at first and second follow-up respectively. Fruit and vegetable intake, level of involvement and demographic variables were assessed by a parental questionnaire. Data was analyzed using multilevel regression analyses. RESULTS: Results showed no effect of the intervention on mothers' fruit and vegetable intake after one year and two year follow-up. Participation rate for the different activities varied by activity and by country, e.g. 3.7-9.4% visited the website, while 26.4-72.6% of the mothers participated in the home work assignments. Results further showed that higher involvement levels were associated with higher intake at follow-up. CONCLUSION: The Pro Children Intervention could not increase the fruit and vegetable consumption of the mothers of participating pupils, which might be explained by the low involvement in the project. More research is needed to increase mothers' involvement in school-based interventions.

The application of a social cognition model in explaining fruit intake in Austrian, Norwegian and Spanish schoolchildren using structural equation modelling.

BACKGROUND: The aim of this paper was to test the goodness of fit of the Attitude - Social influence - self-Efficacy (ASE) model in explaining schoolchildren's intentions to eat fruit and their actual fruit intake in Austria, Norway and Spain; to assess how well the model could explain the observed variance in intention to eat fruit and in reported fruit intake and to investigate whether the same model would fit data from all three countries. METHODS: Samples consisted of schoolchildren from three of the countries participating in the cross-sectional part of the Pro Children project. Sample size varied from 991 in Austria to 1297 in Spain. Mean age ranged from 11.3 to 11.4 years. The initial model was designed using items and constructs from the Pro Children study. Factor analysis was conducted to test the structure of the measures in the model. The Norwegian sample was used to test the latent variable structure, to make a preliminary assessment of model fit, and to modify the model to increase goodness of fit with the data. The original and modified models were then applied to the Austrian and Spanish samples. All model analyses were carried out using structural equation modelling techniques. RESULTS: The ASE-model fitted the Norwegian and Spanish data well. For Austria, a slightly more complex model was needed. For this reason multi-sample analysis to test equality in factor structure and loadings across countries could not be used. The models explained between 51% and 69% of the variance in intention to eat fruit, and 27% to 38% of the variance in reported fruit intake. CONCLUSION: Structural equation modelling showed that a rather parsimonious model was useful in explaining the variation in fruit intake of 11-year-old schoolchildren in Norway and Spain. For Austria, more modifications were needed to fit the data.

Television viewing and exposure to food-related commercials among European school children, associations with fruit and vegetable intake: a cross sectional study.

BACKGROUND: Fruit and vegetable intake is low among European children and exposure to TV is negatively associated with the intake of fruit and vegetables. The aim of the present study was to explore exposure to food commercials on TV in nine European countries. Associations between such exposure and intake of fruit and vegetables and possible mediating effects of attitudes toward and liking of fruit and vegetables were assessed. METHODS: A cross-sectional survey was performed in nine European countries, i.e. Austria, Belgium, Denmark, Iceland, the Netherlands, Norway, Portugal, Spain and Sweden, from October-December 2003, as a part of the Pro Children study. Data on usual intake of fruit and vegetables, and related correlates were collected by means of a self-administered questionnaire among 11-year-old school children (mean age 11.4 (sd = 0.48), 50.2% boys). Complete data was available for 13,035 children. Differences in exposure to TV ads between countries, gender and social class were explored by analysis of variance. Multiple linear regression analysis was used to test associations between exposure to TV ads and intake and to assess mediating effects. RESULTS: The large majority of children in all nine countries report recent exposure to a number of TV ads for food, and they were more often exposed to ads for unhealthy food than for fruit and vegetables (mean of 2.2 (sd = 1.0) unhealthy ads vs. mean of 1.7 (sd = 1.0) healthy ads; p < 0.001). Boys reported somewhat higher TV viewing than girls did (2.5 (sd = 1.7) vs. 2.2 (sd = 1.6) hours per day; p < 0.001), and children from lower social classes reported higher TV viewing than higher social class children did (2.4 (sd = 1.7) vs. 2.0 (sd = 1.5); p < 0.001). Across all countries, exposure to TV ads for healthy foods was positively associated (r = 0.09-0.16) with reported fruit and vegetable intake. This association was in part mediated by attitudes toward and liking of fruit and vegetables. CONCLUSION: Exposure to TV ads for fruit and vegetables appear to be associated with fruit and vegetable consumption among European school children. This relationship is in part mediated through cognitive factors such as attitudes and preferences concerning fruit and vegetables.

Determinants of fruit and vegetable intake among 11-year-old schoolchildren in a country of traditionally low fruit and vegetable consumption.

BACKGROUND: Fruit and vegetable consumption is traditionally low in Iceland. The results of the Pro Children cross-Europe survey showed that the consumption was lowest among children in Iceland. The aim of this study was to identify determinants of fruit and vegetable intake among 11-year-old schoolchildren in Iceland. METHODS: A cross-sectional survey was performed in Iceland in the autumn of 2003 as a part of the Pro Children cross-Europe survey. The survey was designed to provide information on actual consumption levels of vegetables and fruits by 11-year-old school children and to assess potential determinants of consumption patterns. A total of 1235 Icelandic children (89%) from 32 randomly chosen schools participated. Hierarchical regression analyses were performed to determine the explained variance of the children's fruit and vegetable intake. In these analyses socio-demographic background variables were entered as a first block, perceived physical-environmental variables as a second block, perceived socio-environmental variables as a third block and personal variables as a fourth block. RESULTS: 64% of the children ate fruit less than once a day, and 61% ate vegetables less than once a day. Respectively, 31% and 39% of the variance in children's fruit and vegetable intake was explained by the determinants studied. About 7% and 13% of the variance in fruit and vegetable intake was explained by the perceived physical-environmental determinants, mainly by availability at home. About 18% and 16% of the variance in fruit and vegetable intake was explained by the personal determinants. For both fruit and vegetable intake, the significant personal determinants were preferences, liking, knowledge of recommendations and self-efficacy. CONCLUSION: Interventions to increase fruit and vegetable intake among children should aim at both environmental factors such as greater availability of fruit and vegetables, and personal factors as self-efficacy and knowledge levels concerning nutrition.

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.

Correlates of fruit and vegetable consumption among 11-year-old Belgian-Flemish and Dutch schoolchildren.

OBJECTIVE: To determine factors associated with the consumption of fruit and vegetables among 11-year-old schoolchildren in Belgium-Flanders and the Netherlands. DESIGN: In total, 2468 school children from 98 randomly selected schools participated in a cross-sectional survey. VARIABLES MEASURED: Frequency of fruit and vegetable intake and potential personal, social and environmental correlates were measured by means of self-administered, school-based, written questionnaires. ANALYSIS: Hierarchical multiple regression analyses were conducted to assess potential correlates of schoolchildren's fruit and vegetable consumption. Separate analyses were conducted for boys and girls. RESULTS: Bringing fruit to school, modeling behavior of parents and friends, parents demanding that their child eat fruit, knowledge about recommended intake levels, liking fruit, and self-efficacy to eat fruit were the strongest correlates of fruit intake. For vegetables, gender, parental demand, parents facilitating the consumption of vegetables by cutting them for their child, modeling behavior of parents and friends, and preferences for vegetables emerged as strongest correlates. No substantial differences in significant correlates were found according to gender. The percentage of explained variance was 33.7% for fruit and 28.4% for vegetable intake. CONCLUSIONS: Interventions need to be focused on personal (taste preferences), social (parental influences), and environmental factors (availability).

A qualitative exploration of determinants of fruit and vegetable intake among 10- and 11-year-old schoolchildren in the low countries.

BACKGROUND: For the development of fruit and vegetable promotion interventions, insight is needed into determinants of health behaviour. This study presents results of focus group interviews held with 10- to 11-year-old schoolchildren from Ghent (Belgium-Flanders) and Rotterdam (the Netherlands) to explore personal beliefs and motivations and environmental factors related to schoolchildren's fruit and vegetable intake, to inform the Pro Children intervention development. METHODS: Twelve focus groups were held with 92 schoolchildren. The interviews were recorded and transcribed and NVivo was used to analyse the transcripts. RESULTS: Positive health beliefs, taste preferences, lack of knowledge and practical barriers were identified as personal factors related to fruit and vegetable intake. Home and school availability of fruits and vegetables, as well as parenting practices were identified as important environmental factors. CONCLUSION: A fruit and vegetable promotion intervention should aim to increase fruit and vegetable accessibility and should include educational and motivational activities tailored to these personal and environmental factors. These indications should be further evaluated in quantitative research among representative samples.

Personal, social and environmental factors regarding fruit and vegetable intake among schoolchildren in nine European countries.

BACKGROUND/AIMS: Children in Europe are consuming less fruit and vegetables than recommended. Knowledge about the potential determinants of fruit and vegetable intake is vital to understand discrepancies in intake and to guide interventions. The aim of the present study was to assess personal, social and environmental factors regarding fruit and vegetable intake among 11- to 12-year-old children in Europe. METHODS: A cross-sectional survey was undertaken, with nationally or regionally representative samples of in total 13,305 children (mean age 11.4 years) from nine European countries. Pupils in the classroom completed a self-administered questionnaire measuring fruit and vegetable intake and personal, social and environmental factors during one school lesson. Age-adjusted covariance analyses were carried out by gender, for the full sample and for each country separately. Proportions responding positively to the constructs are presented. RESULTS: Overall, European children held a positive attitude towards fruit and vegetable intake. For some constructs, large between-country differences were found. Children had a more positive attitude towards fruit than towards vegetables, and girls were on average more positive than boys. The children perceived their social environment as supportive towards fruit and vegetable intake. They reported good to very good availability of fruit and vegetables at home. However, availability at school and during leisure time activities seemed to be low, both for fruit and for vegetables. CONCLUSION: A large majority of the children reported positively to the personal and social factors regarding fruit and vegetable intake. As regards availability of fruit and vegetables at school and leisure time, and accessibility of fruit and vegetables at home, there is room for improvement.

The pro children intervention: applying the intervention mapping protocol to develop a school-based fruit and vegetable promotion programme.

BACKGROUND/AIMS: The importance of careful theory-based intervention planning is recognized for fruit and vegetable promotion. This paper describes the application of the Intervention Mapping (IM) protocol to develop the Pro Children intervention to promote consumption of fruit and vegetable among 10- to 13-year-old schoolchildren. METHODS: Based on a needs assessment, promotion of intake of fruit and vegetable was split into performance objectives and related personal, social and environmental determinants. Crossing the performance objectives with related important and changeable determinants resulted in a matrix of learning and change objectives for which appropriate educational strategies were identified. Theoretically similar but culturally relevant interventions were designed, implemented and evaluated in Norway, the Netherlands and Spain during 2 school years. RESULTS: Programme activities included provision of fruits and vegetables in the schools, guided classroom activities, computer-tailored feedback and advice for children, and activities to be completed at home with the family. Additionally, optional intervention components for community reinforcement included incorporation of mass media, school health services or grocery stores. School project committees were supported. CONCLUSION: The Pro Children intervention was carefully developed based on the IM protocol that resulted in a comprehensive school-based fruit and vegetable promotion programme, but culturally sensible and locally relevant.

Estrategias educativas para la promoción del consumo de frutas y verduras en el medio escolar: proyecto pro children / School based education strategies to promote fruit and vegetable consumption: the pro children project

Los datos disponibles sugieren que un porcentaje elevado de niños y jóvenes europeos consumen cantidades insuficientes de frutas y verduras. Las estrategias de promoción de hábitos alimentarios saludables y actividad física en el medio escolar tienen un efecto potencial muy positivo. El proyecto Pro Children tiene como finalidad estimar el consumo de frutas y verduras y sus factores determinantes en niños europeos de 11 años y sus familias. También pretende evaluar la eficacia y viabilidad de un programa de educación nutricional orientado a mejorar el consumo de este grupo alimentario. En la primera fase se realizó un estudio transversal en muestra aleatorias representativas de la población de 11 años de 9 países europeos, contemplando análisis de la ingesta y un cuestionario de evaluación de los determinantes del consumo. Se ha diseñado un programa de intervención nutricional en el medio escolar basado en el modelo "Actitudes, Influencias Sociales y Autonomía: (ASE), con un marco teórico similar pero adaptado al contexto sociocultural de cada uno de los países de intervención. A lo largo de dos cursos escolares se evaluará la eficacia del programa en tres países. Cada punto de intervención aplica el programa en 10 centros docentes y considera otros 10 centros control. La planificación de la intervención se realizó siguiendo un procedimiento de mapeo de intervenciones. Se identificaron las conductas a modificar y sus factores determinantes y se formularon los objetivos educativos. Uno de los componentes destacados de la intervención es el suministro de fruta y verdura en el colegio. El programa consta de fichas de actividades para el aula; actividades con la familia; un programa informático de consejo nutricional para los niños y un componente de refuerzo comunitario a elegir para los tres países participantes entre programa de salud escolar; programa en tiendas de alimentación o implicación de los medios de comunicación de masas. A pesar de la diversidad cultural y social, es posible diseñar estrategias similares de intervención con el fin de fomentar el consumo de frutas y verduras en la población escolar. La adpatación a las situaciones específicas favorecerá un mayor éxito