Self-efficacy and norm measures for lunch fruit and vegetable consumption are reliable and valid among fifth grade students

OBJECTIVE: To determine the reliability and validity of a questionnaire measuring fruit and vegetable (FV) self-efficacy and social norms during school lunch among 5th graders. DESIGN: In this cross-sectional study, students completed lunch food records and a psychosocial questionnaire measuring school lunch FV self-efficacy and social norms regarding consumption during the fall and spring semesters. Test-retest reliability was assessed between fall and spring semesters. The measurement model was cross-validated in the spring data. SETTING: One middle school in Houston, Texas. PARTICIPANTS: 275 fifth graders in the 1998 fall semester and 262 of these fifth graders in the 1999 spring semester. MAIN OUTCOME MEASURES: FV consumption and psychosocial variables. ANALYSES: Principal components analyses, confirmatory factor analyses and bivariate correlations. RESULTS: Three scales were identified: Fruit Self-Efficacy, Vegetable Self-Efficacy, and FV Social Norms. FV self-efficacy were positively correlated with low-fat vegetable and fruit consumption. Social norms were positively correlated with total vegetable, low-fat vegetable, fruit and total FV consumption. CONCLUSIONS AND IMPLICATIONS: Self-efficacy and norms for eating FV at school lunch are related to lunch FV consumption. Increasing self-efficacy and social norms about consuming FV at school appears to be important targets to improve FV consumption.     

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

A short food frequency questionnaire (FFQ) to assess fruit and vegetable (F&V) intake was validated. Forty-nine adults and fifty-one adolescents (12-18 years old) completed the FFQ at home, and subsequently kept diet records for seven successive days. Mean daily intake of F&V was overestimated by the FFQ as compared to the 7-day diet records. For adults, spearman correlations of at least 0.5 were observed between the two methods for intake of total fruit and intake of citrus fruit. For adolescents, acceptable spearman correlations (0.53-0.64) were observed between the two methods for total F&V intake, total fruit intake and consumption of fruit juice. Low correlations (0.22-0.35) between the FFQ and the diet records were found for vegetable intake. Relatively large percentages (22-37%) of respondents were incorrectly classified by the short FFQ as eating according to the Dutch recommendations for fruit and vegetable intake. Based on the results of the present study as well as an overview of the results of 34 earlier validation studies of F&V FFQ's, it is concluded that the available FFQ's have only limited capability to make valid assessment of F&V intake levels. In spite of the practical advantages of the short FFQ tested in the present study and the similar validity scores as compared with other often used F&V FFQ's, it needs further revision, especially to be used for valid measurement of vegetable intake as well as total F&V intake among adults.     

Psychosocial predictors of fruit and vegetable consumption among elementary school children

A self-efficacy questionnaire for fruit and vegetable (F&V)consumption among fourth and fifth grade students was developed,pilot tested with 140 students from one school and field testedwith 252 students from two schools. The questionnaire included34 items generated by inventorying behaviors targeted for changein the F&V school curriculum. The four subscales derivedfrom principal components analysis were labeled ‘after-schoolF&V snacks’; ‘breakfast and lunch F&V, andpaying for F&V'; ‘independent shopping for F&V';and ‘assisted shopping for F&V'; they accounted for43.8% of the total variance. Subscale test-re-test reliabilitiesand internal consistencies were acceptable. Criterion validitiesagainst F&V consumption from food records were low. Relationshipswere stronger with preferences and outcome expectations. Resultsfrom stepwise regression analyses indicated that preferenceswere the only significant predictors of fruit and total F&Vconsumption, as well as the main predictor of vegetable consumption;however, the models accounted for less than 13% of the variance.Nutrition education programs which target preferences may bemore effective in increasing F&V consumption among elementaryschool children than programs which target self-efficacy andoutcome expectations. However, since preferences accounted foronly small proportions of the variances, further research shouldconsider other issues such as availability.     

Child-reported family and peer influences on fruit, juice and vegetable consumption: reliability and validity of measures

Family, peers and other environmental factors are likely to influence children's dietary behavior but few measures of these phenomena exist. Questionnaires to measure family and peer influences on children's fruit, juice and vegetable (FJV) consumption were developed and pilot tested with an ethnically diverse group of Grade 4-6 children. Principal components analyses revealed subscales with acceptable internal consistencies that measured parent and peer FJV modeling, normative beliefs, normative expectations, perceived peer FJV norms, supportive and permissive parenting practices, food rules, permissive eating, and child food preparation. Internal consistencies were adequate to high, but test-re-test correlations often were low. Children also completed questionnaires on FJV availability and accessibility in the home, and food records for 2 days in the classroom. Parental modeling, peer normative beliefs and FV availability were significantly correlated with FJV consumption. Further research with these scales is warranted.     

Reliability and validity of a fruit and vegetable screening measure for adolescents.

We developed and evaluated a brief measure of fruit and vegetable consumption for adolescents. The measure was reliable and significantly correlated with 3-day food record data. Correct classification rate (63%) and specificity (63%) were good. Sensitivity (33%) was lower. The measure is recommended, although improvements in classification are still needed.     

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.     

A randomized school trial of environmental strategies to encourage fruit and vegetable consumption among children.

The Cafeteria Power Plus project examined whether a cafeteria-based intervention would increase the fruit and vegetable (FV) consumption of children. Twenty-six schools were randomly assigned to either an intervention or control condition. Baseline lunch observations of a sample (N = 1668) of first- and third-grade students occurred in the spring of 2000; follow-up was in the spring of 2002. The intervention took place during two consecutive school years beginning in the fall of 2000 and consisted of daily activities (increasing the availability, attractiveness, and encouragement for FV) and special events (kick-offs, samplings, challenge weeks, theater production, and finale meal). Training of food-service staff and cook managers was ongoing throughout the intervention phase. Students in the intervention schools significantly increased their total fruit intake. Process measures indicated that verbal encouragement by food-service staff was associated with outcomes. The outcomes suggest that multicomponent interventions are more powerful than cafeteria programs alone with this age group.     

Validation of a tool to measure processes of change for fruit and vegetable consumption among male college students

OBJECTIVE: To develop a valid tool to measure processes of change for fruit and vegetable consumption, and examine the relationship between stage and processes of change among several cultural groups. DESIGN: Cross-sectional, using a self-report questionnaire. SETTING: Convenience sample of male college students living in apartments. PARTICIPANTS: 105 US white, 53 international Latino, and 92 international Asian males. MAIN OUTCOME MEASURES: Fruit and vegetable intake, stage and processes of change characterizations. ANALYSIS: Analysis of covariance, with age as a covariate, was used to determine differences in processes of change scores among 3 cultural groups and stages of change. Two-way analysis of variance investigated relationships between stage of change and fruit and vegetable consumption. The pattern of differences across cultural groups was examined using chi-squared analysis. RESULTS: Self-reported fruit and vegetable intake was higher (P < .01) in action and maintenance than in other stages. Participants in precontemplation/contemplation used significantly less of any process of change than those in preparation or action/maintenance. There were no significant interactions between stage of change and culture for any of the processes of change, but international Asians used significantly more dramatic relief and environmental reevaluation than did US whites and more stimulus control processes than US whites or international Latinos. At all stages, students used significantly more cognitive/experiential processes than behavioral processes. CONCLUSIONS AND IMPLICATIONS: The use of processes increased within action-oriented stages, consistent with previous studies using the Transtheoretical Model in the nutritional area. The greater use of cognitive/experiential than behavioral processes at all stages was not consistent with predictions. Evidence of cultural differences in the use of processes of change was found.     

Measuring attitudes, self-efficacy, and social and environmental influences on fruit and vegetable consumption of 11- and 12-year-old children: reliability and validity

This article examines the reliability and construct validity of questions assessing mediating factors of fruit and vegetable consumption among 11- and 12-year-old children (N=207). Internal consistencies were good for most scales, ranging from 0.56 to 0.94. Intraclass correlation coefficients between test and retest were acceptable, ranging from 0.39 to 0.90. Concerning predictive validity, preferences and perceived parental and peer behavior were significantly associated with fruit and vegetable consumption. Self-efficacy in difficult situations and a variety of available fruit were significantly correlated with fruit consumption, while permissive eating practices and obligation rules were significantly correlated with vegetable consumption. General attitudes, outcome expectations, selection efficacy, and encouraging practices were not associated with fruit or vegetable consumption.     

Factors associated with fruit and vegetable consumption among adults

Background: The higher consumption of fruit and vegetables is considered to be an indicator of healthy eating and the protective effects of fruit and vegetable (FV) consumption for noncommunicable diseases have been investigated extensively. The present study aimed to investigate the association between fruit and vegetable intake (FVI), health behaviours and socio‐demographic factors among adult Canadians. Methods: This analysis was based on the information from the Canadian Community Health Survey, Cycle 3.1. Daily intake of fruit and vegetables from a total number of 15 512 apparently healthy individuals, aged 18–64 years, were assessed using a structured questionnaire, which included 20 questions on the frequency of consumption of different types of fruit and vegetables. Multiple logistic regression models were used to determine the association between FVI and some socio‐economic factors and lifestyle behaviour among adult Canadians. Results: In total 77% of Canadian adults consumed fruit and vegetables less than five times per day. Females were more likely to consume more fruit [odds ratio (OR) 2.05; 95% confidence interval (CI) 1.75–2.4], vegetables (OR 1.95; 95% CI 1.65–2.29) and FV (OR 2.52; 95% CI 2.20–2.90) than males. Single/never married individuals, individuals with higher levels of education, never smokers, former drinkers and older people reported more consumption of fruit and vegetables than others. Conclusions: The results obtained in the present study indicate an association between FVI and some socio‐economic and healthy lifestyle behaviours, and that a substantial gap exists between the recommended level and the actual intake of the FV among the Canadian population. Because a higher intake of FV improves public health, it is imperative to tailor nutrition education at the individual and community levels in Canadian populations.     

Work-to-family spillover and fruit and vegetable consumption among construction laborers

PURPOSE: Spillover is the effect of one role on another as working adults attempt to integrate demands from work and family. We conducted a survey to understand how worker, job, and family characteristics were related to negative work-to-family spillover and how spillover was related to fruit and vegetable consumption to inform intervention design. DESIGN: A combined mail and telephone survey. SETTING: A national random sample in the United States. SUBJECTS: 1108 (44% response) unionized construction laborers. MEASURES: Personal characteristics, job factors, family factors, work-to-family spillover, and fruit and vegetable consumption. ANALYSIS: Multivariable logistic and least-squares regression. RESULTS: A range of 20% to 50% of respondents reported negative work-to-family spillover, agreeing that work demands, time, fatigue, and stress interfered with family meals or food choices. Higher spillover was associated with job factors, being of white race/ethnicity, and having children at home. Lower fruit and vegetable consumption was associated with higher work-to-family spillover (p = .002), being of white race or ethnicity (p < .0001), and working the graveyard or day shift (p = .02). CONCLUSION: Negative experience of work-to-family spillover may link employment to fruit and vegetable consumption and thus to worker health. Understanding the contribution of spillover to fruit and vegetable consumption aids understanding of how work experience affects health.     

Association between parenting styles and own fruit and vegetable consumption among Portuguese mothers of school children

The aim of the present study was to evaluate the association between parenting styles and own fruit and vegetable consumption among Portuguese mothers of school children. A cross-sectional study was performed in Portugal as part of the Pro Children cross-sectional European survey. Portuguese mothers (n 1601) of 11-13-year-old school children were included in the present study. A self-administered questionnaire was developed to assess fruit and vegetable consumption as well as the parenting styles. Fruit and vegetable consumption was assessed by a validated FFQ. Parenting styles based on two dimensions - strictness and involvement - were classified into authoritative, authoritarian, indulgent and neglectful. The higher mean intakes of fruit, vegetables and total fruit and vegetables were observed for mothers classified as indulgent, whereas the lower mean intakes were observed for mothers classified as neglectful. Differences in intake among parenting styles were significant for fruit, vegetables and total fruit and vegetables. When partial correlations were calculated between the two dimensions, strictness and involvement (controlled one for the other), and intakes, only involvement was positively associated with fruit, vegetables and total fruit and vegetable intake. Findings from the present study show that fruit and vegetable consumption of Portuguese mothers of school children seems to be related to their own parenting styles, especially with the dimension involvement. Future interventions to promote fruit and vegetable intake should take into account these variables.     

Environmental determinants of fruit and vegetable consumption among adults: a systematic review

The current ecological approach in health behaviour research recognises that health behaviour needs to be understood in a broad environmental context. This has led to an exponential increase in the number of studies on this topic. It is the aim of this systematic review to summarise the existing empirical evidence pertaining to environmental influences on fruit and vegetable (FV) consumption. The environment was defined as 'all factors external to the individual'. Scientific databases and reference lists of selected papers were systematically searched for observational studies among adults (18-60 years old), published in English between 1 January 1980 and 31 December 2004, with environmental factor(s) as independent factor(s), and fruit intake, vegetable intake or FV intake combined as one outcome measure as dependent factor(s). Findings showed there was a great diversity in the environmental factors studied, but that the number of replicated studies for each determinant was limited. Most evidence was found for household income, as people with lower household incomes consistently had a lower FV consumption. Married people had higher intakes than those who were single, whereas having children showed mixed results. Good local availability (e.g. access to one's own vegetable garden, having low food insecurity) seemed to exert a positive influence on intake. Regarding the development of interventions, improved opportunities for sufficient FV consumption among low-income households are likely to lead to improved intakes. For all other environmental factors, more replicated studies are required to examine their influence on FV intake.     

Improving fruit and vegetable consumption: use of farm-to-consumer venues among US adults

Improvements to the food environment including new store development and more farm-to-consumer approaches (ie, farmers' markets, roadside stands, pick-your-own produce farms, or community-supported agriculture programs) may aid Americans in making healthier dietary choices. We analyzed data from a subset of respondents (N = 1,994) in the National Cancer Institute's Food Attitudes and Behaviors Survey, a mail survey of US adults. We determined associations between primary grocery shoppers' region and sociodemographic characteristics and frequency of purchasing fruits and vegetables in the summer from farm-to-consumer venues. A little more than one-quarter (27%) of grocery shoppers reported a frequency of at least weekly use of farm-to-consumer approaches. Older adults and respondents who live in the Northeast were most likely to shop farm-to-consumer venues at least weekly, and no differences were found by sex, race/ethnicity, education, or annual household income. These findings suggest that farm-to-consumer venues are used by many Americans and could be expanded to increase access to fruits and vegetables.     

Psychosocial correlates of fruit and vegetable consumption among African American men

OBJECTIVE: To determine the best predictors of fruit and vegetable consumption among African American men age 35 years and older. DESIGN: Data (n = 291) from a 2001 nationally representative mail survey commissioned by the American Cancer Society. PARTICIPANTS: 291 African American men age 35 years and older. MAIN OUTCOME MEASURES: Dependent variables: (1) total fruits and vegetables without fried potatoes, (2) total fruit with juice, and (3) total vegetables without fried potatoes. Independent variables included 3 blocks of predictors: (1) demographics, (2) a set of psychosocial scales, and (3) intent to change variables based on a theoretical algorithm. ANALYSIS: Linear regression models; analysis of variance for the intent to change group. Alpha = .05. RESULTS: Regression model for total fruits and vegetables, significant psychosocial predictors: social norms, benefits, tangible rewards, and barriers-other. Total fruit with juice: social norms, benefits, tangible rewards. Total vegetables, no fried potatoes: tangible rewards, barriers-other interests. CONCLUSIONS AND IMPLICATIONS: For African American men, fruit consumption appears to be motivated by perceived benefits and standards set by important people in their lives; vegetable consumption is a function of extrinsic rewards and preferences for high-calorie, fatty foods. The results suggest that communications to increase fruit and vegetable consumption should be crafted to reflect differences in sources of motivation for eating fruits versus eating vegetables.     

Increasing fruit and vegetable consumption among 4th and 5th grade students: results from focus groups using reciprocal determinism

The Year 2000 Goals for the U.S. identify a goal of five servings per day of fruits and vegetables (F&V), which is roughly double what children are currently eating. Focus group discussions (based on the reciprocal determinism concept in social learning theory) were conducted with 4th and 5th grade students, their parents, teachers, and school food service workers, in preparation for the design of a school nutrition education program to increase consumption of F&V. A social learning theory perspective was taken because it has been demonstrated to be useful in the design of effective school nutrition education programs. A theory-based protocol delineating the sequence of questions to be asked in each focus group was designed before each group met. Discussions were conducted with ten groups of students, two groups each of teachers and of parents, and one of school food service employees. Three general factors appeared to be most likely to increase F&V consumption in these children: increasing availability of F&V in the home, enhancing liking for vegetables, and providing skills in increasing F&V availability and in preparing F&V.     

Food prices and fruit and vegetable consumption among young American adults

Multivariate negative binomial count models were estimated to examine associations between young adults’ fruit and vegetable (FV) consumption and the prices of FV, other food at home grocery items, and fast food and the availability of restaurants and food stores. This study used the 2002 wave of data collected from US young adults aged 18–23 years in the 1997 National Longitudinal Survey of Youth merged by geocode identifiers with food prices and restaurant and food store availability. The results showed that higher levels of FV consumption were associated with lower FV prices (price elasticity of −0.32) and that this own-price effect was robust to the inclusion of other food prices and food outlet availability. Lower income and lower educated young adults and those with lower educated mothers and middle-income parents were found to be most price sensitive. No statistically significant cross-price effects on FV consumption were found with other grocery food (meat, dairy and bread) prices or fast food prices. Fiscal policy instruments such as FV subsidies may help to increase FV intake, particularly among young adults of lower socioeconomic status.