According to a new report published in the Archives of Disease in Childhood, there needs to be a revision in the UK and the US of the recommended amount of physical activity children need to prevent obesity. Currently, only 42% of boys and about 11% of girls are achieving the weekly recommended levels.
Researcher Brad S. Metcalf (Department of Endocrinology and Metabolism, Peninsula Medical School, Plymouth, UK) and colleagues draw their conclusions from monitoring, beginning at age 5, 113 boys and 99 girls who attended 54 different schools. The samples come from a larger project that tracks 307 children born between 1995 and 1996 called the EarlyBird study.
Each child wore a tiny device around his waste that would track weekly physical activity. In addition, every year between the ages of 5 and 8, the children received measurements of weight, insulin resistance, blood fat and cholesterol levels, blood pressure, and other predictive health indicators. These indicators, including measurements of body mass index (BMI), were chosen based on their ability to predict cardiovascular disease and diabetes.
In order to prevent obesity and associated health problems, the guidelines in both the UK and US suggest that moderate physical activity for at least an hour every day is ideal for children. The analysis conducted by Metcalf and colleagues indicated a wide range of physical activity actually measured – from 10 minutes per day to 90 minutes per day. About 11% of girls and 42% of boys completed the recommended activity levels. However, there was no significant difference in change in BMI between those who did and those who did not meet the guidelines.
Among boys and girls who did the recommended level of physical activity, there were noticeable improvements in their predictive health indicators. However, in the less active children, there were noticeable deteriorations in these indicators.
The authors conclude with a summary of the three main findings from their report: “First, children who regularly spend more time engaged in physical activity at the intensity recommended by the current guidelines appear to benefit in metabolic health although not in BMI…It may be that current guidelines are adequate, but the outcome measure used to monitor them (BMI) is too blunt…Second, girls undertake systematically less physical activity than boys, and it is unclear whether the guideline should be lowered for girls, to allow for what may be a biological difference, or particular encouragement given to girls to do more…Finally, relatively few children achieve the current guideline. To extend the positive health benefits shown here to less active children, we first need to understand why some undertake more physical activity than others, and this may not be straightforward.”
Physical activity at the government-recommended level and obesity-related health outcomes: a longitudinal study
B S Metcalf, L D Voss, J Hosking, A N Jeffery, T J Wilkin
Archives of Disease in Childhood (2008).
doi 10.1136/adc.2007.135012
Click Here to Journal Website
Written by: Peter M Crosta