Location: Children's Nutrition Research Center2011 Annual Report
1a. Objectives (from AD-416)
Objective 1: Identify risk factors, moderators, and mediators for obesity and obesity-related behaviors, including dietary, physical activity, and lifestyle factors using extant datasets. Sub-objective 1A: Determine differences in diet quality among obese, overweight, and normal weight children among a nationally representative sample. Sub-objective 1B: Examine walking or biking to school, objective physical activity, and weight status in adolescents. Sub-objective 1C: Examine the association of television viewing (TV) with source of food, eating occasion, and portion size. Sub-objective 1D: Determine associations between objectively measured physical activity and markers of insulin resistance and cardiovascular disease in US children and adolescents. Sub-objective 1E: Determine the relationship between dietary energy density, obesity, and the metabolic syndrome among adolescents.
1b. Approach (from AD-416)
We will conduct cross-sectional data analyses of National Health and Nutrition Examination Survey (NHANES) and will focus on the following: diet quality, active commuting to school, television and video viewing, physical activity, and dietary energy density among nationally representative samples of US youth to determine associations with obesity and related disorders. We will identify potential dietary underreporting by using gender and age group specific cutoffs for reported energy intake as a percentage of predicted energy requirements as previously developed by USDA funded research. We will use linear/logistic regression analyses and stratify by socio-demographics to determine the highest at-risk groups for poor diet quality. Since Healthy Eating Index (HEI)-2005 assesses diets on a per 1000 calorie basis, it will not be necessary to control for diet quantity or energy intake for these analyses. To identify potential socio-demographic disparities in the association between moderate to vigorous physical activity and markers of insulin resistance and cardiovascular disease, interactions with gender, race/ethnicity, and income will be examined.
3. Progress Report
The overall project objective was to conduct analyses using the National Health and Nutrition Examination Survey administered by the US Centers for Disease Control and Prevention to identify risk factors, moderators, and mediators of childhood obesity. We examined walking and bicycling to school (active commuting to school) among youth and the association with moderate-to-vigorous physical activity, adiposity, and obesity. A manuscript of this work was published in the May 2011 issue of the Journal of Physical Activity and Health. We also conducted analyses examining the association between children's adiposity and their diet quality, as measured by the USDA's Healthy Eating Index-2005. A revised manuscript of this work is under review at a peer-reviewed biomedical journal. We examined youth physical activity and the relationship to risk factors for heart disease and diabetes. A manuscript of this work is under review at a peer-reviewed biomedical journal. The ADODR monitors project activities by visits, review of purchases of equipment, review of ARS-funded foreign travel, and review of ARS funds provided through the SCA.
1. General versus central adiposity and relationship to pediatric metabolic risk. The influence of physical activity and body fatness on pediatric metabolic risk is not well described. Researchers at the Children's Nutrition Research Center, in Houston, TX, used the US National Health and Nutrition Examination Survey for analyses examining the relationship between youth physical activity, body fatness (body mass index z-score and waist circumference), and risk factors for cardiovascular disease and diabetes. Researchers found that greater physical activity was related to lower metabolic risk. For two of the risk factors, this relationship was accounted for by lower waist circumference. Lower waist circumference was also related to multiple improved risk factors. These findings suggest the need for clinical and public health programs to screen for and improve youth physical activity and waist circumference.