Project Number: 6250-51000-053-00
Project Type: Appropriated

Start Date: Mar 31, 2009
End Date: Mar 30, 2014

Objective:
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.

Approach:
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.