Energy Expenditure, Diet and Body Fat in Children
Condition: Cardiovascular Diseases; Heart Diseases; Obesity
MeSH terms: Cardiovascular Diseases; Heart Diseases
Study type: Observational

Summary: 
      To characterize the pattern of change over a two year period in energy expenditure and energy
      intake in two cohorts of American Indian (AI) children.
    

Detailed description: 
      BACKGROUND:

      Obesity is highly prevalent in American Indian children, increasing their risk for the
      development of cardiovascular disease, hypertension and diabetes. Although increasing energy
      expenditure, through increasing physical activity, and decreasing dietary fat intake should
      slow the rate of body fat gain, it appears that children actually decrease their physical
      activity as they mature from pre-to post-pubescence. Several studies have shown that the
      decline in activity is greater in females than in males, and greater in non-whites than in
      whites; however, other studies have not supported these findings. Further, there were no data
      available in American Indian children, which is a population at greatest risk. Additionally,
      inconsistencies have been reported with respect to the relationship between body weight or
      body fat and energy intake or dietary fat intake. At the heart of the problem is the
      difficulty in measuring self-reported physical activity and dietary intake accurately.
      Accurate self- report measures are necessary for use in the large scale studies that are
      required to investigate relationships between physical activity and dietary intake and
      disease. The Healthy People 2000: National Health Promotion and Disease Prevention Objectives
      include seven objectives emphasizing increasing physical activity in children and
      adolescents.

      DESIGN NARRATIVE:

      This study had a combined longitudinal and cross-sectional design in which the investigators
      modified the best existing methods for the self-report of physical activity and dietary
      intake in children and adolescents, and evaluated their validity using total energy
      expenditure (TEE) measured by doubly labeled water (DLW) as the criterion. They then used
      these methods to measure physical activity and dietary intake in two age cohorts of male and
      female American Indian children (8-10-years and 11-13-years) at baseline and two years later,
      with two sets of interim measurements. Change in TEE from baseline to the two-year follow-up
      was also measured using DLW and the TriTrac accelerometer. Equations for the estimation of
      percent body fat were cross-validated for this population. The study filled an existing gap
      by improving existing instruments for the measurement of physical activity and dietary intake
      in children and adolescents, and provided longitudinal data on change in these variables in
      the same children over time, plus provided cross-sectional data for each age and gender group
      to compare to the existing literature.

      The study completion date listed in this record was obtained from the "End Date" entered in
      the Protocol Registration and Results System (PRS) record.