Reliability and validity of food portion size estimation from images using manual flexible digital virtual meshes.

OBJECTIVE: The eButton takes frontal images at 4s intervals throughout the day. A three-dimensional manually administered wire mesh procedure has been developed to quantify portion sizes from the two-dimensional images. The present paper reports a test of the inter-rater reliability and validity of use of the wire mesh procedure. DESIGN: Seventeen foods of diverse shapes and sizes served on plates, bowls and cups were selected to rigorously test the portion assessment procedure. A dietitian not involved in inter-rater reliability assessment used standard cups to independently measure the quantities of foods to generate the 'true' value for a total of seventy-five 'served' and seventy-five smaller 'left' images with diverse portion sizes. SETTING: The images appeared on the computer to which the digital wire meshes were applied. SUBJECTS: Two dietitians and three engineers independently estimated portion size of the larger ('served') and smaller ('left') images for the same foods. RESULTS: The engineers had higher reliability and validity than the dietitians. The dietitians had lower reliabilities and validities for the smaller more irregular images, but the engineers did not, suggesting training could overcome this limitation. The lower reliabilities and validities for foods served in bowls, compared with plates, suggest difficulties with the curved nature of the bowls. CONCLUSIONS: The wire mesh procedure is an important step forward in quantifying portion size, which has been subject to substantial self-report error. Improved training procedures are needed to overcome the identified problems.

Predicting habits of vegetable parenting practices to facilitate the design of change programmes.

OBJECTIVE: Habit has been defined as the automatic performance of a usual behaviour. The present paper reports the relationships of variables from a Model of Goal Directed Behavior to four scales in regard to parents' habits when feeding their children: habit of (i) actively involving child in selection of vegetables; (ii) maintaining a positive vegetable environment; (iii) positive communications about vegetables; and (iv) controlling vegetable practices. We tested the hypothesis that the primary predictor of each habit variable would be the measure of the corresponding parenting practice. DESIGN: Internet survey data from a mostly female sample. Primary analyses employed regression modelling with backward deletion, controlling for demographics and parenting practices behaviour. SETTING: Houston, Texas, USA. SUBJECTS: Parents of 307 pre-school (3-5-year-old) children. RESULTS: Three of the four models accounted for about 50 % of the variance in the parenting practices habit scales. Each habit scale was primarily predicted by the corresponding parenting practices scale (suggesting validity). The habit of active child involvement in vegetable selection was also most strongly predicted by two barriers and rudimentary self-efficacy; the habit of maintaining a positive vegetable environment by one barrier; the habit of maintaining positive communications about vegetables by an emotional scale; and the habit of controlling vegetable practices by a perceived behavioural control scale. CONCLUSIONS: The predictiveness of the psychosocial variables beyond parenting practices behaviour was modest. Discontinuing the habit of ineffective controlling parenting practices may require increasing the parent's perceived control of parenting practices, perhaps through simulated parent-child interactions.

Obesity status trajectory groups among elementary school children.

BACKGROUND: Little is known about patterns in the transition from healthy weight to overweight or obesity during the elementary school years. This study examined whether there were distinct body mass index (BMI) trajectory groups among elementary school children, and predictors of trajectory group membership. METHODS: This is a secondary analysis of 1651 elementary school children with complete biannual longitudinal data from kindergarten to the beginning of 5(th) grade. Heights and weights were measured by trained school nurses using standard procedures at the beginning and end of each school year for 11 consecutive assessments. Group-based trajectory clustering and multinomial logit modeling were conducted. RESULTS: When using BMIz score, six trajectory groups were identified revealing substantial consistency in BMIz score across time. When using a categorical variable separating overweight/obese children (BMI ≥ 85%ile) from the rest, five developmental trajectories (persistently non-overweight/obese weight: 51.1 %; early-onset overweight/obese: 9.2 %; late-onset overweight/obese: 9.7 %; becoming healthy weight: 8.2 %; and chronically overweight/obese: 21.8 %) were identified. When using a categorical variable separating obese children (BMI ≥ 95%ile) from the rest, three trajectories (persistently non-obese: 74.1 %, becoming obese: 12.8 %; and chronically obese: 13.2 %) were identified. For both cutoffs (≥ BMI percentile 85 % or 95 %), girls were more likely than boys to be classified in the persistently non-overweight and/or obese group (odds ratios (OR) ranged from 0.53 to 0.67); and Hispanic children and non-Hispanic Black children were more likely to be chronically overweight and/or obese than non-Hispanic White children (OR ranged from 1.57 to 2.44). Hispanic children were also more likely to become obese (OR: 1.84) than non-Hispanic White children when ≥ BMI percentile 95 % was used. CONCLUSIONS: Boys, Hispanic and non-Hispanic Black children were at higher risk of being overweight or obese throughout their elementary school years, supporting the need for obesity treatment. Post kindergarten and post second grade summer months were times when some children transitioned into overweight/obesity. It will be important to identify which behavioral factors (e.g., diet, physical activity, sedentary behaviors, and/or sleep) predisposed children to becoming overweight/obese, and whether these factors differ by time (Kindergarten versus second grade). If behavioral predisposing factors could be identified early, targeted obesity prevention should be offered.

Creating action plans in a serious video game increases and maintains child fruit-vegetable intake: a randomized controlled trial.

BACKGROUND: Child fruit and vegetable intake is below recommended levels, increasing risk for chronic disease. Interventions to influence fruit and vegetable intake among youth have had mixed effects. Innovative, theory-driven interventions are needed. Goal setting, enhanced by implementation intentions (i.e., plans tightly connected to a behavioral goal), may offer a solution. Action plans state "how" a goal will be achieved, while coping plans identify a potential barrier and corresponding solution. The research reported here evaluated the short- and long-term effects of goal setting enhanced with implementation intentions on child fruit and vegetable intake in a 10-episode, theoretically-grounded serious videogame promoting fruit and vegetables. This is one of the first studies to test the efficacy of implementation intentions on the dietary intake of healthy children. METHODS: A four-group randomized design with three data collection periods (baseline, immediate post-intervention, 3 months post-intervention) was employed. Groups varied on whether children created an implementation intention (none, action, coping, both) as part of goal setting. Participants were 4th and 5th grade children (~9-11 years old) and one parent. An a priori power analysis indicated this would provide >80% power to detect a small effect (Cohen's d = 0.17). Children played a 10-episode online videogame; parents received 10 electronic newsletters and access to a parent-only website. The primary outcome was child fruit and vegetable intake, assessed via three, dietitian-assisted telephone recalls at each data collection period. The primary analysis was conducted using a repeated measures analysis of covariance with a mixed model procedure. Secondary analyses examined intervention effects on fruit and vegetables separately. RESULTS: Four hundred parent/child dyads were recruited. A significant group-by-time interaction for fruit and vegetable intake (p < 0.001) was found in only the Action group, which had significant increases in fruit and vegetable intake at post 1 (p < 0.0001) and post 2 (p < 0.0001). No other significant interactions were observed; however, there were significant time effects for fruit (p < 0.0001). CONCLUSIONS: Action intentions may be an important component of successful interventions to increase and maintain fruit and vegetable intake in pre-adolescent children. Videogames promoting healthy diets offer an effective vehicle for delivering behavior change interventions to children. TRIAL REGISTRATION: ClinicalTrials.gov NCT01004094 .

Predicting use of effective vegetable parenting practices with the Model of Goal Directed Behavior.

OBJECTIVE: To model effective vegetable parenting practices using the Model of Goal Directed Vegetable Parenting Practices construct scales. DESIGN: An Internet survey was conducted with parents of pre-school children to assess their agreement with effective vegetable parenting practices and Model of Goal Directed Vegetable Parenting Practices items. Block regression modelling was conducted using the composite score of effective vegetable parenting practices scales as the outcome variable and the Model of Goal Directed Vegetable Parenting Practices constructs as predictors in separate and sequential blocks: demographics, intention, desire (intrinsic motivation), perceived barriers, autonomy, relatedness, self-efficacy, habit, anticipated emotions, perceived behavioural control, attitudes and lastly norms. Backward deletion was employed at the end for any variable not significant at P<0·05. SETTING: Houston, TX, USA. SUBJECTS: Three hundred and seven parents (mostly mothers) of pre-school children. RESULTS: Significant predictors in the final model in order of relationship strength included habit of active child involvement in vegetable selection, habit of positive vegetable communications, respondent not liking vegetables, habit of keeping a positive vegetable environment and perceived behavioural control of having a positive influence on child's vegetable consumption. The final model's adjusted R 2 was 0·486. CONCLUSIONS: This was the first study to test scales from a behavioural model to predict effective vegetable parenting practices. Further research needs to assess these Model of Goal Directed Vegetable Parenting Practices scales for their (i) predictiveness of child consumption of vegetables in longitudinal samples and (ii) utility in guiding design of vegetable parenting practices interventions.

Predicting use of ineffective vegetable parenting practices with the Model of Goal Directed Behavior.

OBJECTIVE: Increasing a parent's ability to influence a child's vegetable intake may require reducing the parent's use of ineffective vegetable parenting practices. The present study was designed to understand the psychosocial influences on ineffective vegetable parenting practices. DESIGN: A cross-sectional web-based survey was conducted to model use of ineffective vegetable parenting practices using validated scales from a Model of Goal Directed Vegetable Parenting Practices. SETTING: The dependent variable was a composite ineffective vegetable parenting practices index. The independent variables included validated subscales of intention, habit, perceived barriers, desire, competence, autonomy, relatedness, attitudes, norms, perceived behavioural control and anticipated emotions. Models were analysed using block regression with backward deletion. SUBJECTS: Parents of 307 pre-school children (3-5 years old). RESULTS: Variables significantly positively related to ineffective vegetable parenting practices in order of relationship strength included habit of controlling vegetable practices (standardized ß=0·349, P<0·0001) and desire (standardized ß=0·117, P=0·025). Variables significantly negatively related to ineffective vegetable parenting practices in order of relationship strength included perceived behavioural control of negative parenting practices (standardized ß=-0·215, P<0000), the habit of active child involvement in vegetable selection (standardized ß=-0·142, P=0·008), anticipated negative parent emotional response to child vegetable refusal (standardized ß=-0·133, P=0·009), autonomy (standardized ß=-0·118, P=0.014), attitude about negative effects of vegetables (standardized ß=-0·118, P=0·015) and descriptive norms (standardized ß=-0·103, P=0·032). The model accounted for 40·5 % of the variance in use of ineffective vegetable parenting practices. CONCLUSIONS: The present study is the first report of psychometrically tested scales to predict use of ineffective vegetable parenting practices. Innovative intervention procedures will need to be designed and tested to reduce ineffective vegetable parenting practices.

Vegetable parenting practices scale. Item response modeling analyses.

OBJECTIVE: To evaluate the psychometric properties of a vegetable parenting practices scale using multidimensional polytomous item response modeling which enables assessing item fit to latent variables and the distributional characteristics of the items in comparison to the respondents. We also tested for differences in the ways item function (called differential item functioning) across child's gender, ethnicity, age, and household income groups. METHOD: Parents of 3-5 year old children completed a self-reported vegetable parenting practices scale online. Vegetable parenting practices consisted of 14 effective vegetable parenting practices and 12 ineffective vegetable parenting practices items, each with three subscales (responsiveness, structure, and control). Multidimensional polytomous item response modeling was conducted separately on effective vegetable parenting practices and ineffective vegetable parenting practices. RESULTS: One effective vegetable parenting practice item did not fit the model well in the full sample or across demographic groups, and another was a misfit in differential item functioning analyses across child's gender. Significant differential item functioning was detected across children's age and ethnicity groups, and more among effective vegetable parenting practices than ineffective vegetable parenting practices items. Wright maps showed items only covered parts of the latent trait distribution. The harder- and easier-to-respond ends of the construct were not covered by items for effective vegetable parenting practices and ineffective vegetable parenting practices, respectively. CONCLUSIONS: Several effective vegetable parenting practices and ineffective vegetable parenting practices scale items functioned differently on the basis of child's demographic characteristics; therefore, researchers should use these vegetable parenting practices scales with caution. Item response modeling should be incorporated in analyses of parenting practice questionnaires to better assess differences across demographic characteristics.

Simulated adaptations to an adult dietary self-report tool to accommodate children: impact on nutrient estimates.

OBJECTIVE: To simulate the effect of child-friendly (CF) adaptations of the National Cancer Institute's Automated Self-Administered 24-Hour Dietary Recall (ASA24) on estimates of nutrient intake. METHOD: One hundred twenty children, 8-13 years old, entered their previous day's intake using the ASA24 and completed an interviewer-administered recall using the Nutrition Data System for Research (NDSR). Based on a hypothesis that proposed adaptations to the ASA24 will not significantly affect mean nutrient estimates, ASA24 data were manipulated postadministration to simulate a CF version in which 2 categories of data collection were removed: (1) foods not likely to be consumed by children (45%) based on previous analyses of national dietary data and (2) food detail questions (probes) to which children are unlikely to know the answers (46%), based on our experience. RESULTS: Mean estimates of select nutrients between the beta version of ASA24 and the simulated CF recall showed no significant differences, indicating that the food and probe elimination did not significantly affect results. However, a comparison of total sugar and vitamin C assessments between the original ASA24, the CF version, and NDSR showed that the daily nutrient totals for both nutrients were significantly higher in the self-administered methods (both ASA24 and CF version) than in NDSR (interviewer-administered), which warrants a review of different methods for obtaining information about foods that are sources of these nutrients. CONCLUSION: The simulation of CF adaptations showed that it is feasible to implement, thereby reducing CF response burden without significantly affecting the results.

Psychometric assessment of scales for a Model of Goal Directed Vegetable Parenting Practices (MGDVPP).

BACKGROUND: Vegetable intake has been related to lower risk of chronic illnesses in the adult years. The habit of vegetable intake should be established early in life, but many parents of preschoolers report not being able to get their child to eat vegetables. The Model of Goal Directed Behavior (MGDB) has been employed to understand vegetable parenting practices (VPP) to encourage a preschool child's vegetable intake. The Model of Goal Directed Vegetable Parenting Practices (MGDVPP) provides possible determinants and may help explain why parents use effective or ineffective VPP. Scales to measure effective and ineffective vegetable parenting practices have previously been validated. This manuscript presents the psychometric characteristics and factor structures of new scales to measure the constructs in MGDVPP. METHODS: Participants were 307 parents of preschool (i.e. 3 to 5 year old) children, used for both exploratory (EFA) and confirmatory factor analyses (CFA). Data were collected via an internet survey. First, EFA were conducted using the scree plot criterion for factor extraction. Next, CFA assessed the fit of the exploratory derived factors. Then, classical test theory procedures were employed with all scales. Finally, Pearson correlations were calculated between each scale and composite effective and ineffective VPP as a test of scale predictive validity. RESULTS: Twenty-nine subscales (164 items) within 11 scales were extracted. The number of items per subscale ranged from 2 to 13, with three subscales having 10 or more items and 12 subscales having 4 items or less. Cronbach's alphas varied from 0.13 to 0.92, with 17 being 0.70 or higher. Most alphas <0.70 had only three or four items. Twenty-five of the 29 subscales significantly bivariately correlated with the composite effective or ineffective VPP scales. DISCUSSION: This was the initial examination of the factor structure and psychometric assessment of MGDVPP scales. Most of the scales displayed acceptable to desirable psychometric characteristics. Research is warranted to add items to those subscales with small numbers of items, test their validity and reliability, and characterize the model's influence on child vegetable consumption.

TV parenting practices: is the same scale appropriate for parents of children of different ages?

PURPOSES: Use multidimensional polytomous item response modeling (MPIRM) to evaluate the psychometric properties of a television (TV) parenting practices (PP) instrument. Perform differential item functioning (DIF) analysis to test whether item parameter estimates differed across education, language, or age groups. METHODS: Secondary analyses of data from three studies that included 358 children between the ages of 3 and 12 years old in Houston, Texas. TV PP included 15 items with three subscales: social co-viewing, instructive parental mediation, and restrictive parenting. The multidimensional partial credit model was used to assess the performance. DIF was used to investigate the differences in psychometric properties across subgroups. RESULTS: Classical test theory analyses revealed acceptable internal consistency reliability (Cronbach's α: 0.72 to 0.83). More items displaying significant DIF were found across children's age groups than parental education or language groups. A Wright map revealed that items covered only a restricted range of the distribution, at the easier to respond end of the trait. CONCLUSIONS: TV PP scales functioned differently on the basis of parental education, parental language, and child age, with the highest DIF among the latter. Additional research is needed to modify the scales to minimize these moderating influences. Some items may be age specific.

Influences on children's dietary behavior, and innovative attempts to change it.

Fruit and vegetable (FV) intake may protect against several chronic diseases, and the preferences and habits in relation to FV intake appear to form in early childhood. Child FV intake reflects many influences from multiple levels (e.g. internal to the child, family, school, and neighborhood). We have documented influences at each of these levels, but more definitive research in longitudinal samples remains to be conducted. Even though validated comprehensive models of influences on child FV intake in longitudinal studies are not available to guide intervention design for children of different ages, there has been an urgency to initiate chronic disease prevention interventions to mitigate the substantial health consequences. Effective interventions use known behavior change procedures to change the influences on FV intake enough to change the behavior, but few such interventions have demonstrated effectiveness at meaningful levels. Innovative methods need to be explored. Videogames for Health offer a medium that is attractive to children and shows promising results, especially for dietary behavior change. Exciting additional research is needed to clarify possible bidirectional influences between the environmental and individual influences on child intake with possible age-related differences in influence and in the optimal design of video games for dietary change.

Dimensions of vegetable parenting practices among preschoolers.

The objective of this study was to determine the factor structure of 31 effective and ineffective vegetable parenting practices used by parents of preschool children based on three theoretically proposed factors: responsiveness, control and structure. The methods employed included both corrected item-total correlations and confirmatory factor analysis. Acceptable fit was obtained only when effective and ineffective parenting practices were analyzed separately. Among effective items the model included one second order factor (effectiveness) and the three proposed first order factors. The same structure was revealed among ineffective items, but required correlated paths be specified among items. A theoretically specified three factor structure was obtained among 31 vegetable parenting practice items, but likely to be effective and ineffective items had to be analyzed separately. Research is needed on how these parenting practices factors predict child vegetable intake.

A model of goal directed vegetable parenting practices.

The aim of this study was to explore factors underlying parents' motivations to use vegetable parenting practices (VPP) using the Model of Goal Directed Vegetable Parenting Practices (MGDVPP) (an adaptation of the Model of Goal Directed Behavior) as the theoretical basis for qualitative interviews. In-depth interviews with parents of 3-5-year-old children were conducted over the telephone by trained interviewers following a script. MGDVPP constructs provided the theoretical framework guiding script development. Audio-recordings were transcribed and analyzed, with themes coded independently by two interviewers. Fifteen participants completed the study. Interviews elicited information about possible predictors of motivations as they related to VPP, and themes emerged related to each of the MGDVPP constructs (attitudes, positive anticipated emotions, negative anticipated emotions, subjective norms, and perceived behavioral control). Parents believed child vegetable consumption was important and associated with child health and vitality. Parents described motivations to engage in specific VPP in terms of emotional responses, influential relationships, food preferences, resources, and food preparation skills. Parents discussed specific strategies to encourage child vegetable intake. Interview data suggested parents used diverse VPP to encourage child intake and that varied factors predicted their use. Understanding these factors could inform the design of interventions to increase parents' use of parenting practices that promote long-term child consumption of vegetables.

The Children's Behavior Questionnaire very short scale: psychometric properties and development of a one-item temperament scale.

Little research has been conducted on the psychometrics of the very short scale (36 items) of the Children's Behavior Questionnaire, and no one-item temperament scale has been tested for use in applied work. In this study, 237 United States caregivers completed a survey to define their child's behavioral patterns (i.e., Surgency, Negative Affectivity Effortful Control) using both scales. Psychometrics of the 36-item Children's Behavior Questionnaire were examined using classical test theory, principal factor analysis, and item response modeling. Classical test theory analysis demonstrated adequate internal consistency and factor analysis confirmed a three-factor structure. Potential improvements to the measure were identified using item response modeling. A one-item (three response categories) temperament scale was validated against the three temperament factors of the 36-item scale. The temperament response categories correlated with the temperament factors of the 36-item scale, as expected. The one-item temperament scale may be applicable for clinical use.

Components of the diet associated with child adiposity: a cross-sectional study.

OBJECTIVE: This study sought to determine which components of youths' diets were related to adiposity while controlling for potential often-neglected confounders such as moderate to vigorous physical activity (MVPA) and dietary reporting error. Secondary goals of this study were to determine the extent to which MVPA confounded the associations between diet and adiposity and whether associations between diet and adiposity would differ depending on reporting error. METHODS: An ethnically diverse urban sample of 342 children aged 9-10 years and 323 adolescents aged 17-18 years were recruited for this cross-sectional study. Body mass index (BMI) and waist circumference (WC) were measured in the school; dietary assessment included three 24-hour recalls via telephone in the evenings, and MVPA assessment included 5 days of accelerometry. Over (n = 68), under (n = 250), or plausible (n = 347) dietary intake reporters were identified with the Huang calculation method. Linear regression assessed the relationship between adiposity indicators (BMI z-score and WC) and components of the diet (energy intake, food groups, macronutrients) after controlling for reporting error, demographic variables, and MVPA. RESULTS: When dietary reporting error and potential confounders such as MVPA and demographic variables were controlled, energy intake (EI), vegetables, refined grains, total fat, total protein, and total carbohydrate were positively related to BMI z-score and WC and artificially sweetened beverages to WC. MVPA was a significant confounder. For BMI z-score, but not WC, relationships and strength of these relationships differed depending on dietary reporting error group (plausible, underreporter, overreporter). CONCLUSIONS: Among plausible reporters, as expected, EI, refined grains, and all macronutrients were positively related to adiposity; however, artificially sweetened beverages and vegetables, which are low-energy-dense foods, were also positively related to adiposity. Reporting error interfered with associations between diet and BMI z-score but not WC, suggesting WC is a more robust measure of adiposity in relation to diet.

Children's accuracy of portion size estimation using digital food images: effects of interface design and size of image on computer screen.

OBJECTIVE: To test the effect of image size and presence of size cues on the accuracy of portion size estimation by children. DESIGN: Children were randomly assigned to seeing images with or without food size cues (utensils and checked tablecloth) and were presented with sixteen food models (foods commonly eaten by children) in varying portion sizes, one at a time. They estimated each food model's portion size by selecting a digital food image. The same food images were presented in two ways: (i) as small, graduated portion size images all on one screen or (ii) by scrolling across large, graduated portion size images, one per sequential screen. SETTING: Laboratory-based with computer and food models. SUBJECTS: Volunteer multi-ethnic sample of 120 children, equally distributed by gender and ages (8 to 13 years) in 2008-2009. RESULTS: Average percentage of correctly classified foods was 60·3 %. There were no differences in accuracy by any design factor or demographic characteristic. Multiple small pictures on the screen at once took half the time to estimate portion size compared with scrolling through large pictures. Larger pictures had more overestimation of size. CONCLUSIONS: Multiple images of successively larger portion sizes of a food on one computer screen facilitated quicker portion size responses with no decrease in accuracy. This is the method of choice for portion size estimation on a computer.

Overeating styles and adiposity among multiethnic youth.

Reasons for inconsistent associations between overeating styles and adiposity among youth may include differences in effects by age, gender, or ethnicity; failure to control for social desirability of response; or adiposity measurement limitations. This study examined the relationship between overeating styles and multiple measures of adiposity, after controlling for social desirability and testing for moderation by ethnicity, age, and gender. Data from 304 9-10 year old children and 264 17-18 year old adolescents equally representing African American, Hispanic, and White ethnic groups were extracted from a larger cross-sectional study. Measures included the Dutch Eating Behavior Questionnaire (restrained, external, and emotional overeating subscales), the "Lie Scale" from the Revised Children's Manifest Anxiety Scale, and measured weight, height, waist circumference, and triceps skinfold. BMI z-score and a global adiposity index were calculated. Mixed model linear regression showed restraint was positively and external eating was negatively related to measures of adiposity. African American youth had a stronger inverse association between emotional eating and adiposity than White or Hispanic youth. Relationships were not influenced by social desirability nor moderated by age or gender. Overeating styles are related to adiposity in nearly all youth but the nature of these associations are moderated by ethnicity.

Self efficacy for fruit, vegetable and water intakes: Expanded and abbreviated scales from item response modeling analyses.

OBJECTIVE: To improve an existing measure of fruit and vegetable intake self efficacy by including items that varied on levels of difficulty, and testing a corresponding measure of water intake self efficacy. DESIGN: Cross sectional assessment. Items were modified to have easy, moderate and difficult levels of self efficacy. Classical test theory and item response modeling were applied. SETTING: One middle school at each of seven participating sites (Houston TX, Irvine CA, Philadelphia PA, Pittsburg PA, Portland OR, rural NC, and San Antonio TX). SUBJECTS: 714 6th grade students. RESULTS: Adding items to reflect level (low, medium, high) of self efficacy for fruit and vegetable intake achieved scale reliability and validity comparable to existing scales, but the distribution of items across the latent variable did not improve. Selecting items from among clusters of items at similar levels of difficulty along the latent variable resulted in an abbreviated scale with psychometric characteristics comparable to the full scale, except for reliability. CONCLUSIONS: The abbreviated scale can reduce participant burden. Additional research is necessary to generate items that better distribute across the latent variable. Additional items may need to tap confidence in overcoming more diverse barriers to dietary intake.

6-n-Propylthiouracil sensitivity and obesity status among ethnically diverse children.

OBJECTIVE: To examine the relationship of 6-n-propylthiouracil (PROP) sensitivity to BMI while statistically controlling for demographic characteristics in two age groups of children: 9-10 years and 17-18 years (n 1551). DESIGN: Cross-sectional design with a multi-ethnic (White, African-American, Hispanic, Other) sample of 813 children aged 9-10 years and 738 children aged 17-18 years. Children were recruited from local elementary and high schools with at least 30 % minority ethnic enrolment. Children's height, weight and waist circumference were measured along with their PROP taster status. PROP was measured using two paper discs, one impregnated with NaCl (1.0 mol/l) and the other with PROP solution (0.50 mmol/l). RESULTS: A significant PROP sensitivity by socio-economic status (SES) interaction term (P = 0.010) was detected wherein supertasters had the largest BMI percentile and Z-score, but only among the group with highest SES. CONCLUSIONS: The results suggest that other factors overwhelmed the influence of PROP sensitivity on adiposity in lower-SES groups. The percentage of variance accounted for by the interaction term was about 1 %. Thus, PROP supertasters had the largest BMI percentile and Z-score, but only among the highest-SES group.

Parenting practices are associated with fruit and vegetable consumption in pre-school children.

OBJECTIVE: Parents may influence children's fruit and vegetable (F&V) consumption in many ways, but research has focused primarily on counterproductive parenting practices, such as restriction and pressure to eat. The present study aimed to assess the association of diverse parenting practices to promote F&V and its consumption among pre-school children. DESIGN: An exploratory analysis was performed on cross-sectional data from 755 Head Start pre-school children and their parents collected in 2004-5. Data included parent practices to facilitate child F&V consumption (grouped into five categories); parent-reported dietary intake of their child over 3 d; and a number of potential correlates. K-means cluster analysis assigned parents to groups with similar use of the food parenting practice categories. Stepwise linear regression analyses investigated the association of parent clusters with children's consumption of F&V, after controlling for potential confounding factors. RESULTS: A three-cluster solution provided the best fit (R2 = 0.62), with substantial differences in the use of parenting practices. The clusters were labelled Indiscriminate Food Parenting, Non-directive Food Parenting and Low-involved Food Parenting. Non-directive parents extensively used enhanced availability and teachable moments' practices, but less firm discipline practices than the other clusters, and were significantly associated with child F&V intake (standardized beta = 0.09, P < 0.1; final model R2 = 0.17) after controlling for confounders, including parental feeding styles. CONCLUSIONS: Parents use a variety of parenting practices, beyond pressuring to eat and restrictive practices, to promote F&V intake in their young child. Evaluating the use of combinations of practices may provide a better understanding of parental influences on children's F&V intake.