Researchers from the Peninsula Medical School in Plymouth, UK, have carried out research that suggests the one hour of moderate exercise a day recommended to children from health experts may not be enough to tackle the rising problem of childhood obesity.
Their research has been published in the most recent issue of the journal "Archives of Diseases in Childhood."
The results come from the EarlyBird study, which has followed the development of over 200 children in Plymouth born in 1995 and 1996.
Researchers found that when these children were aged between five and eight, 42 per cent of boys and only 11 per cent of girls met the government recommended daily exercise level of one hour of moderate exercise.
The study also found that exercise alone had no positive effect on weight control over time, although the research team were keen to stress that this does not mean that exercise has no health benefits for children.
Indeed, when compared with peers who took less exercise, children who met the recommended activity levels fared better for blood pressure, cholesterol, triglycerides and insulin resistance, which is a recognised precursor to type 2 diabetes later in life.
However the researchers did believe that improving children's diets, which they claim to have "changed markedly" over the last two decades, would be likely to have a greater impact on their overall health and weight.
Dr. Brad Metcalf, researcher in the Department of Endocrinology and Metabolism at the Peninsula Medical School, commented: " We are keen to stress that children should be encouraged to be active, because our study showed that regular exercise improved metabolic health even without improving BMI."
The research team worked with 212 children from 54 schools in Plymouth and followed them for four years. Once a year the children were tested by wearing small monitors that recorded their exercise levels.
The amount of physical activity achieved by children each day varied considerably – some only managed 10 minutes of moderate exercise, while others went over 90 minutes.
Said Dr. Metcalf: "The results for girls are in line with past research that shows that young girls do not exercise as much as boys. To some degree any child's activity level can be affected by biology – some children are more naturally active than others and this might explain why there is such a marked difference between boys and girls. At present it is unclear whether exercise guidelines should be adjusted for this difference, or whether girls should be encouraged to exercise more."