The most effective way for teenagers to prevent obesity appears to be getting involved in three or more sports each year, US researchers have found.
Researchers from Dartmouth College in New Hampshire found those teenagers who play three or more team sports per year are 27 percent less likely to be overweight or obese.
Plus, kids who walk or bike to school on more than four days each week are less likely to be obese.
Keith Drake and colleagues from the Geisel School of Medicine at Dartmouth analysed data from phone surveys they conducted with more than 1700 high school students. Of those, 29 percent were overweight or obese and 13 percent were obese.
"I know that coordinating schedules can be difficult in terms of getting kids to practices and games. But it does look to us like getting kids involved in sports may be the best chance we have to get them physically active and to help them maintain a healthy body weight," Drake told MSNBC.
The researchers questioned the students about diet, academic performance, weight and sport participation. Almost 75 percent played team sport, with 17 percent playing on one team, 19 percent on two teams and 33 percent on three or more teams.
"High school sports participation typically involves regular practices and competitions, leading to consistent moderate to strenuous activity, which may explain the strength of its relationship with weight status compared with other forms of physical activity," Drake wrote in the August issue of Pediatrics.
"Increasing opportunities for all adolescents, regardless of athletic ability, to participate in sports should be prioritised for obesity prevention."
Those who played one team sport experienced some advantages, but the biggest impact on being overweight or obese occurred amongst those who played three or more sports per year.
In Australia, 24.9 percent of children aged between five and 17 are overweight or obese.