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This is the VOA Special English Education Report.

Too much eating. Too many unhealthy foods. Too many advertisements for food. Too little activity.

Different explanations are offered for America's weight problem 体重问题-- a problem increasingly shared by other countries. Almost one-fifth of American children and teenagers are overweight.

Schools have been urged to increase physical education, an important tool for public health. And many have. Yet now comes a study showing an increase in the number of injuries in "phys ed" class. Injuries increased one hundred fifty percent between nineteen ninety-seven and two thousand seven.

The study involved injuries treated in hospital emergency departments急症室. Only two percent were serious.

The researchers did not try to identify the causes of the increase, but they have some theories.

Lara McKenzie from Ohio State University 俄亥俄州立大学was the lead researcher. She s