Topical Area: Nutrition Education and Behavioral Science, Obesity
Objectives : Obesity during childhood and adolescence is a risk factor for several types of chronic disease in adulthood. Researchers have identified dietary energy density (ED, kcal/g) and sedentary behavior as risk factors for obesity during adulthood, but little is known about the relationship between diet and measured cardiovascular fitness levels. The 2012 National Health and Nutrition Examination Survey National Youth Fitness Survey (NNYFS) collected data on dietary intake, physical activity and fitness levels in a nationally representative sample of US adolescents. The objective of this study was to determine the association between eating patterns, specifically dietary energy density, and physical fitness in a nationally representative sample of youth.
Methods : Using data from NHANES National Youth Fitness Survey, the association between dietary energy density (ED, kcal/g) and cardiovascular fitness level was evaluated. During the NNYFS, cardiovascular fitness was assessed in adolescents aged 12-15y. Dietary intake information was collected using 24-hour recall, and assessment of diet quality involved calculation of dietary energy density. Cardiovascular fitness level was categorized based on gender-age specific cut-points of estimated VO2max. All data were analyzed using SAS 9.4 survey procedures to account for the unequal sampling probability and complex survey design of the NHANES.
Results : We observed a significant positive association between dietary energy density and cardiovascular fitness level after controlling for age, sex, race, and household income. Children with cardiovascular fitness levels categorized as “high risk” had significantly higher dietary energy density than children in the “healthy fitness zone” (1.82 vs 1.97, p=0.04).
These findings expand on previous work from our group indicating that dietary energy density is associated with obesity in children and that diet in early childhood corresponds with development of physical characteristics that are associated with fitness ability. Interventions that aim to lower dietary energy density in adolescence may aid in the reduction of chronic disease risk during adulthood.
Funding Sources : None.