2009 Annual Report
1a.Objectives (from AD-416)
Childhood obesity is a major public health problem in the U.S. and successful approaches to prevent obesity are needed. The prevalence of overweight in preschool children has more than doubled in the past two decades. Currently, a third of children in the United States are at risk of overweight, while 17% are overweight. A greater concern is that most existing obesity prevention intervention approaches thus far have been found to be largely ineffective. Diverse novel behavioral, genetic, and biological methods and models are needed to better understand the causes and find effective ways to combat this problem. Children's Nutrition Research Center scientists will address these issues through targeting the following research objectives:.
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;.
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;.
3)investigate the effectiveness of community-based intervention strategies to prevent childhood obesity and its associated health risks in 8- to 12-y-old Hispanic children with BMI >/= 85th percentile;.
4)develop and evaluate family-centered intervention strategies for the pediatric primary care setting to prevent childhood obesity;.
5)develop and evaluate the effectiveness of a culturally appropriate, web-based, dietary and physical activity intervention for preventing obesity in high school students;.
6)develop and evaluate the effectiveness of novel, multi-media, diet and/or physical activity interventions for preventing obesity in youth;.
7)develop and evaluate a model of childhood obesogenic environments based on parent-child dynamics affecting child eating behaviors and body weight status;.
8)determine environmental factors and eating pattern typologies associated with obesity and related diseases in children, adolescents, and young adults using extant datasets;.
9)identify promising theoretical approaches, mediators, and intervention components of nutrition and physical activity behavior change in children using extant datasets; 10) identify risk factors, moderators, and mediators for obesity and obesity-related behaviors, including dietary, physical activity and lifestyle factors using extant datasets; 11) evaluate relationships between parent and child beliefs about physical activity, and their relationship with child physical activity, sedentary behavior, and weight status using extant datasets; 12) determine obesity-related metabolic and body composition responses to exercise programs with and without a dietary intervention in lean and obese adolescents; and 13) develop and test pilot interventions to increase and sustain physical activity at a level consistent with the Dietary Guidelines for Americans (DG) in urban African- and Mexican-American children and families.
1b.Approach (from AD-416)
A multidimensional approach will be undertaken to address the obesity research conducted at the Children's Nutrition Research Center. In summary, investigators will address childhood obesity through research in genetics, biology, behavioral modeling, and by the implementation of a wide range of interventions. Researchers will investigate the effects of a controlled exercise program alone as compared to exercise with a diet intervention and determine the impact on numerous biological measures of the research participants. Genes related to satiety or physical activity signaling pathways will be examined by researchers as they learn the association of eating and physical activity experiences in children. Additional research will permit new models of how known genes may be influencing diet and physical activity practices. Researchers will develop, test, and validate innovative youth behavioral models and validate a measure of youth physical activity problem solving ability. Additional models will be developed to understand the functional relationships of behavioral factors that influence the weight status of children, as a result of examining parent and child characteristics (individually and combined) to ascertain their contributions to the probability of pediatric obesity. Model refinement will occur by employing dyadic and mixture modeling approaches to account for latent heterogeneity in how these factors are functionally inter-related within the given population. Assessment of the validity of current theories of obesity-related behavior change will be conducted through mediating variable analyses of existing datasets. Several interventions will be conducted in order to establish functional programs that will reduce obesity and/or further weight gain. A family-based randomized controlled trial will be conducted to test the effectiveness of diet behavior modification, structured aerobic exercise, or diet behavior modification plus structured aerobic exercise for obesity prevention and improvement in fitness, health risks, and psychological state in at-risk children. Research studies will also evaluate the effectiveness of a culturally appropriate, web-based, dietary and physical activity intervention for preventing obesity in high school students when compared with a control group. Weight, dietary and physical activity behaviors, and psychosocial mediating variables will be measured and compared to determine the effectiveness of specific web-based interventions. Furthermore, as a result of these interventions, models will be developed and formative work performed to evaluate the developed model for obesity prevention.
We have begun to look at composite models linking genes and obesity through mediating psychosocial and behavioral variables. (Project.
1)We have genotyped 25 SNPs that we identified in a large cohort of Hispanic children phenotyped for diet, physical activity, and weight gain. A manuscript has been submitted for publication. We have developed a theory-based conceptual model for an obesity Prevention Plus Intervention based on literature searches. We conducted and analyzed 13 interviews with parents regarding goal setting for a lifestyle Prevention Plus program. We are currently submitting an IRB protocol for additional interviews with parents of overweight 5- to 8-year olds as a needs assessment for obesity Prevention Plus Program. (Project.
2)The website is being programmed and will be completed by 9/1/09. Game development was completed and beta testing conducted. Needed changes were made, and the game was finalized and prepared for the pilot study. Parent newsletters were finalized, the parent web site was developed. Recruitment and enrollment materials and procedures were developed, and a manual of procedures was created. Dietary data collection staff was hired and trained. Data collection scales were finalized and programmed. Recruitment and data collection for the pilot study were completed, and the pilot study initiated. Recruitment for the outcome evaluation is scheduled to begin in October, 2009. Statistical analyses were conducted to examine item functioning within scales, and correlations among scales in the model were also analyzed. Modifications were made as indicated to enhance scale quality. Additionally, to facilitate recruitment and data collection, the questionnaire was programmed as an online survey, procedures were developed, the online survey was beta tested, and the online study launched (i.e., recruitment and data collection initiated). (Project.
3)A manuscript will be submitted to the Journal of Nutrition Education Behavior within a month entitled: Feeding Style Differences in Food Parenting Practices Associated with Fruit and Vegetable Intake in Children. This manuscript describes the development of the strategies parents use to get their children to eat healthy and supports the validity of the constructs by relating strategies (referred to as food parenting practices) to parent feeding styles and child fruit and vegetable intake. (Project.
4)Analysis occurred using data from extant datasets and appropriate manuscripts were written. (Project 5)
Snacking is Associated with Reduced Risk for Overweight and Reduced Abdominal Obesity in Adolescents: NHANES, 1999-2004: Adolescents are nutritionally vulnerable due to the poor dietary patterns and the parallel increase in overweight. Although snacking is common, it is unclear if snacking plays a role in overweight within the context of the overall diet. Children's Nutrition Research Center researchers conducted a secondary analysis of 24-hour diet recall and anthropometric data from the National Health and Examination Survey, 1999-2004 in order to examine the associations of snacking with weight status and abdominal obesity in adolescents 12- to 18-years-of age (n = 5,811). We found that the mean weight, BMI, the percentile of BMI-for-age, and waist circumference were all inversely associated with both snacking frequency and percentage of energy from snacks. The prevalence of overweight/obesity, and the prevalence of abdominal obesity also decreased with increasing snacking frequency, and with increasing percentage of energy from snacks. From these results, the data indicates that adolescents who consumed snacks were less likely than those who did not to be overweight or obese, and were less likely to have abdominal obesity. (Project 5: Understanding Environmental Factors and Behavioral Changes for Childhood Obesity Prevention)
The Impact of Dairy and Sweetened Beverage Consumption on Head Start Mothers: Mothers with children in Head Start play a critical role in providing healthy diets and modeling good dietary behaviors to their children, but there is little information available on their diet, especially on beverage consumption. Children's Nutrition Research Center researchers assessed the association of milk and sweetened beverage consumption with nutrient intake, dietary adequacy, and weight of a multiethnic population of Head Start mothers. Using a cross sectional, secondary analysis, African-American (43%), Hispanic-American (33%), and European-American (24%) women were divided into four beverage consumption groups: high milk/low sweetened beverages, high milk/high sweetened beverages, low milk/low sweetened beverages, and low milk/high sweetened beverage consumption. We found that women in the high milk/low sweetened beverage consumption group consumed more nutrient dense foods and that the overall consumption of milk was low in this overall population. Additionally the consumption of high milk/low sweetened beverages was associated with improved nutrient intake, including the short fall of nutrients: calcium, potassium, magnesium, and vitamin A. (Project 5: Investigation of dietary intakes of children)
Predictors of Calcium Intake from Ethnically Diverse Families with Limited Incomes: A study was conducted to determine the associations between beverage intake of mothers and their young children from ethnically diverse families with limited incomes. Children's Nutrition Research Center researchers reviewed a 2004-2005 data set of 465 Mother-Child groups from Head Start families that were composed of 41% African American (AA), 34% Hispanic American (HA), and 21% White (W). We found that the percentage of mothers and children consuming sweetened beverages at dinner meals exceeded that for milk, except for white children. Additionally, milk and cheese consumption predicted the most variance in calcium intake for both mother and child overall and for all race-ethnic groups. It can be determined that replacing sweetened beverages at dinner meals with milk or 100% fruit juice would be a strategy to improve the nutrient density of the diets of families with limited incomes. (Project 5: Investigation of dietary intakes of children)
Relationship Between Breakfast Consumption with Children/Adolescent's Nutrient Intake and Weigh Status: US data comparing nutrient intakes and body weight measures in children and adolescents who skip breakfast or consume different types of breakfasts are limited. Children's Nutrition Research Center researchers examined the relationship between the types of breakfast consumed and breakfast skipping with nutrient intake, nutrient adequacy, and weight status in children and adolescents. Approximately 9,500 subjects (9-13 years and 14-18 years) were examined from the 1999-2006 National Health and Nutrition Examination Survey cross-sectional dataset: 20.1% children and 31.5% adolescents were breakfast skippers; 35.9% children and 25.4% adolescents were Ready-to-eat cereal breakfast consumers. From our analysis we were able to conclude that Ready-to-eat cereal breakfast consumers had favorable nutrient intake profiles and weight status indices than other breakfast consumers or breakfast skippers in children and adolescents. (Project 5: Investigation of dietary intakes of children)
Environmental Influences on Childhood Obesity: Developing a model that explains aspects of the child's immediate environment that promote or contribute to childhood obesity (such as parenting behaviors that influence child eating) is an important and necessary tool for the current scientific community to better understand causes of obesity. Children's Nutrition Research Center scientists along with other research collaborators (Tufts University; Save the Children organization; University of Alabama at Birmingham; Michigan State University; and Baylor College of Medicine) conducted analyses to determine the impact of parent feeding styles (authoritarian, authoritative, indulgent, and uninvolved) on a number of important factors. These researchers conceptualized a "multiple approach to parenting" in the food arena which includes both warmth and control in parent-child eating interactions and an appropriate level of structure in the home around food so that children can learn to develop a healthy relationship with food, greater evidence for the feeding style questionnaire by associating feeding styles with child food intake and child weight status after accounting for parent's emotions during parent-child interactions (both positive and negative emotions) and other factors such as parent weight and ethnicity, and general parenting and child weight status among rural families in four states. Specific information about general feeding styles (which reflects child rearing attitudes among parents) and more specific food parenting practices (such as insisting that your child eat everything on the plate) in conjunction with how well parent emotions and child personality traits complement each other during parent-child interactions will inform the research community so that better interventions can be developed to reduce overweight in young children. (Project 4: Development of Obesity-Related Eating Behaviors in Childhood)