Physical activity interventions for children have small impact on overall activity levels and consequently the body fat and mass of children, a study published on bmj.com today suggests.There is no need for further studies.
Previous studies have shown that greater activity levels are associated with lower levels of BMI (body mass index) but that physical activity interventions have been unsuccessful in improving children's BMI. Many previous reviews have not, however, confined their analyses to whole-day activity and some relied on questionnaires rather than objective measures of physical activity like pedometers to measure daily steps taken. This is the first systematic review to measure physical activity using accelerometry devices which provide a measure of total bodily movement across waking hours...
The authors conclude that in the mind of the public, physical inactivity is a major cause of childhood obesity and although the need to increase it is intuitive the "small increase gained from formal interventions seems insufficient to improve the body mass / fat of children." They suggest that further studies should capture both whole day activity and activity related to intervention-specific periods.
In an accompanying editorial, authors from University College London suggest that the study's chosen method of analysis does have "inherent limitations" although the results provide the best evidence to date on the effectiveness of activity interventions in childhood. They suggest that the focus of other studies should also shift away from overweight and obese children and instead look at outcomes that relate to improving health in children regardless of their weight. Hamer and Fisher suggest that future research should focus on how changes to the indoor and outdoor environment can encourage children's activity.
The work has been done.
Find it here, here and here.