Studying the children for over a two-year period, the researchers observed that higher greenness was significantly associated with lower body mass index (BMI) in kids.
In previous studies of adults, residential density tended to predict physical activity levels, with highly urban environments leading to more walking, less driving and lower BMI.
According to researchers, greenness might indicate proximity to parks, playfields or other open spaces that promote either physical activity or increased time spent outdoors in active play.
"This study's findings align with previous research linking exposure to green landscapes with health improvements," said Janice F. Bell, PhD, MPH, Assistant Professor in the department of Health Services at the School of Public Health and Community Medicine, University of Washington, Seattle.
"Among adults, greenness is associated with less stress and lower BMI, improved self-reported health and shorter post-operative recovery periods. Among children and youth, the positive health effects of green landscapes include improved cognitive functioning and reduced attention deficit hyperactivity disorder symptoms.
"Ideally, future research in this area will be multidisciplinary - involving city planners, architects, geographers, psychologists and public health researchers - and will consider the ways children live and play in urban environments," she added.
The article published in the December 2008 issue of the American Journal of Preventive Medicine.