The number of North American children who are obese-- who have more body face than do 85 percent of North American child

问题描述:

The number of North American children who are obese-- who have more body face than do 85 percent of North American children their age--is steadily increasing.求破折号内的翻译,谁和谁做比较

意思就是
北美的过度肥胖儿童的数量呈稳步上升的趋势.
与其他85%的同龄人相比,他们要更多的面对自己的身体问题.