Submitted to: International Journal of Obesity
Publication Type: Peer reviewed journal
Publication Acceptance Date: 12/16/1997
Publication Date: N/A
Citation: Interpretive Summary: Obesity is an increasing health problem in the United States, affecting as many as 27 percent of all U.S. children and adolescents. Some studies report that obese children are less active than normal-weight children, while others report no difference. We wanted to determine whether overweight children have lower physical activity energy expenditure and fitness levels than normal-weight children. We studied 24 healthy girls ag 7 to 10 years and divided them into overweight and non-overweight groups. We used methods including doubly labeled water, room calorimetry, and a treadmill test. We found that the overweight girls did not have lower physical activity energy expenditure or fitness levels than the non-overweight prepubertal girls after adjusting for differences in body composition. This information will be useful in further research on obesity and its origins.
Technical Abstract: OBJECTIVE: To determine whether overweight children have lower physical activity energy expenditure (EE) and fitness levels than non-overweight children. STUDY DESIGN: Twenty-four healthy girls age 7-10 yr were divided into overweight (>95th percentile weight-for-height) and non-overweight (10 -90th percentile) groups. Basal metabolic rate (BMR), sleeping metabolic rate (SMR), 24-h sedentary EE (SEE) and total EE (TEE) were measured by room respiration calorimetry and doubly labeled water. Physical activity EE and physical activity level (PAL) were calculated. Fitness (VO2peak) was measured by a treadmill exercise test. RESULTS: The overweight group had significantly higher body weight, percent fat, fat mass and fat-free mass (FFM) (P<0.001). The overweight girls had higher BMR, SMR, SEE and TEE (P<0.001), but not after adjustment for FFM. Physical activity EE and PAL were not significantly different between groups. After adjusting for FFM or weight, submaximal and peak VO2 were not significantl different between groups. CONCLUSIONS: We conclude that these overweight girls do not have lower physical activity EE or fitness levels than the non-overweight prepubertal girls, however, the rather high body fat of the non-overweight group may have precluded us from finding any differences between groups.