2013 Annual Report
1a.Objectives (from AD-416):
The long-term objective of this project is to develop improved understanding of how genes influence obesity-related behaviors through experiences of food intake and physical activity, and whether these experiences mediate the gene to behavior relationships. We will focus on the following objectives that will be studied concurrently within the same experiments.
Objective 1: Determine the extent to which relationships between appetite-related genetic factors and dietary intake are mediated by subjective feelings of hunger, satiety, and other psychosocial variables in children.
Subobjective 1A: Generate a questionnaire that assesses food and physical activity related experiences in middle school students.
Subobjective 1B: Test whether food and physical activity related experiences mediate the gene to dietary intake and physical activity relationships.
Objective 2: Determine the extent to which relationships between activity-related genetic factors and physical activity are mediated by subjective feelings of enjoyment and related psychosocial variables in children.
1b.Approach (from AD-416):
Children's Nutrition Research Center researchers will conduct a literature review of possible experiential aspects of genes in regard to diet and physical activity (e.g., satiety, enjoyment of physical activity). Knowledge gained from these reviews will permit the researchers to conduct focus group discussions to generate items that reflect these possible gene experiences, and convert the statements to items in a questionnaire. Our scientific team will conduct cognitive interviewing with children to ensure the items are understood by the children. We will distribute the questionnaires for completion by large numbers of children on which to conduct the psychometric analyses. The accretion of adiposity among 3rd and 4th grade students over the summer will be studied. The above questionnaires and the genetic variables will be used, and associated relationships will be evaluated.
The execution of this study on the behavioral pathways of biological influences on energy balance, specifically looking at the genetics of satiety amongst Hispanic children, requires a significant amount of resources and unfortunately these were not available during the fiscal year. We expect to identify and secure these resources in FY14 as part of our video game research from whom we are collecting blood samples, and will primarily need to find funds to do the genotyping. This year we made a major advance in understanding influences on vegetable parenting practices. We learned that parents who are trying to get their reluctant preschool child to eat vegetables use six categories of parenting practices, three of which are characterized as ineffective, and three as effective. It appears that parents use both and are not aware of the differences in effectiveness. We have tested a model of psycho-emotional predictors of effective and ineffective vegetable parenting practices, which accounted for almost 50% of the variability (which is very high for this kind of research), and hope that these findings will lead to the development of programs to train parents in more effective vegetable parenting practices for preschoolers. We received support to develop a video game to enable parents of preschoolers to get their child to eat more vegetables. This is a follow up to a previous grant that developed a single session prototype of such a game. We have been productizing and revising the Diab and Nanoswarm video games. This has taken much longer than expected, but should result in a game that is more likely to effectively change children's diet and physical activity behaviors. The outcome evaluation trial should begin in January 2014. We are also testing the hypothesis that adding a story to exergames will elicit more physical activity from players over a longer period of time. This research will initiate at the end of this fiscal year. We anticipate support to take the next steps in developing a camera-image-based method of dietary assessment among children. This method would combine the work we have done in creating a computerized child self-administered 24-hour dietary recall with new technology developed by collaborators at the University of Pittsburgh that takes and processes picture images at 2-second intervals throughout the day. This passive diet assessment system offers promise of substantially enhancing the accuracy of diet assessment among children. We have conducted secondary analyses of the HEALTHY data set (a multi-site middle school intervention study in which we participated) and showed that while increases in fitness over three years were related to BMI category change, the primary predictor was baseline BMI. This indicates that interventions to prevent obesity should start earlier than middle school. We have reviewed the relevant literature to reveal that contrary to popular belief, most weight gain among overweight children occurs in the summer, with weight loss during the school year. This is in contrast to healthy weight children who accumulate more weight during the school year. This suggests that schools are part of the solution, not a part of the problem. This project should provide guidance to school health policy.
Categorizing ways that parents get kids to eat vegetables. There has been no theory-based measure that assesses both likely to be effective and likely to be ineffective vegetable parenting practices for use in research with young children (3-5 years old). Researchers at the Children's Nutrition Research Center in Houston, Texas, developed a measure that included 31 items across theory-predicted responsiveness (or warmth), control and structure (or supportiveness of the environment) aspects of both effective and ineffective vegetable parenting practices. The predicted categories were confirmed by analysis of questionnaire data, and the pattern of findings suggests that parents use both effective and ineffective practices. The questionnaire is now available as a resource for use by researchers to study the development of young children's eating habits.
Scales for a Model of Goal-Directed Vegetable Parenting Practices (MGDVPP). 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) adds emotional and motivational variables to existing highly predictive models to understand why people do (or do not do) targeted behaviors. The Model of Goal-Directed Vegetable Parenting Practices provides possible determinants and may help explain why parents use effective or ineffective vegetable parenting practices. Researchers at the Children's Nutrition Research Center in Houston, Texas, developed new scales to measure constructs in MGDVPP which include 164 items extracted from questionnaire data. These scales are now available for use by researchers who are interested in understanding or encouraging parents' use of effective and ineffective vegetable parenting practices.
Categorizing ways that parents influence their child's TV watching. Behavioral researchers focusing on obesity prevention in children question whether the same scale of how parents influence their children's TV use is appropriate for parents of children of different ages. Researchers at the Children’s Nutrition Research Center in Houston, Texas, combined data from three existing studies that included 358 children between the ages of 3 and 12 years of age. Their analyses revealed that items worked differently across the children's age groups, more than across parental education or language groups. We now know that researchers will need to modify the scales to minimize differences in measurement across children of different ages.
Adapting an adult dietary self-report tool to children. It is not clear whether the National Cancer Institute's Automated Self-Administered 24-Hour Dietary Recall (ASA24) that was simplified to meet the needs of children still provides accurate estimates of nutrient intake. Researchers at the Children's Nutrition Research Center in Houston, Texas, adapted the ASA24 to be child-friendly by removing: (1) foods not likely to be consumed by children based on previous analyses of national dietary data and (2) food detail questions (probes) to which children are unlikely to know the answers. No differences were found between the ASA24 and the simulated child-friendly recall, except for total sugar and vitamin C. This research demonstrated that it is feasible to reduce child response burden without significantly affecting the nutrient results.
Conference report on energy balance related parenting practices. Although parents are believed to provide strong influence on children's behavior, severe problems have been identified in measures of obesity-related (i.e., diet, physical activity, and screen media) parenting practices. These problems have inhibited the quality of the research in this area, and to change this situation, researchers at the Children's Nutrition Research Center in Houston, Texas, held a conference and from this were able to develop a special report. The conference presentations reviewed the relevant literature and working group discussions and identified research needed to bring clarity and precision to measures of these constructs. The publications from the presentations and working group discussions will appear as a special issue of Childhood Obesity. Several groups who attended the conference are now developing new measures of obesity-related parenting practices, which offers a promise of improving research in this area.