【单选题】

According to studies cited by the NationalEatingDisordersAssociation, 42 percent of girls in first through third grade want to be thinner, 81 percent of 10-year-olds are afraid of being fat, and 51 percent of 9-and 10-year-old girls feel better about themselves if they are on a diet.

In many ,ways, this fixation on weight at ever earlier ages comes at an inopportune time physiologically.At a recent Hadassah meeting at the WoodlandsCommunity Temple in White Plains,Dr. Maxcie Schneider, the director of adolescent medicine at Greenwich Hospital, andErica Leon, a registered dietitian, spoke about early adolescence as a time when a little bit of pudginess is necessary for proper growth, and youngsters wrestle constantly with their body image.
"I can’t tell you how many kids I’ve seen who’ve been on theAtkins diet, or on the SouthBeach diet," Ms. Leon said, adding that overweight children who try diets can be at risk of developing eating disorders.
After the presentation, three mothers from Hartsdale who wanted to help their children avoid such issues spoke about how their young daughters are already beginning to become weight-conscious.
Anorexia is a mental illness in which the victim eats barely enough to survive, because her distorted thinking makes her think she is fat.Bulimia, a mental illness in which someone binges on large amounts of food, then purges it through vomiting or the abuse of laxatives, is on the rise, and is surfacing in younger and younger patients, mostly girls, said Judy Scheel, the director of theCenter forEatingDisorder Recovery in Mount Kisco.
About 90 percent of victims of eating disorders are female, and often the male victims are on teams like wrestling and crew, where they must keep their weight low for competitive reasons.Dr. Scheel believes that where girls claim the eating disorder enables them to be thin, boys typically state their goal is to achieve or maintain a muscular but thin physique. The average onset for bulimia used to be 17, but to see teenagers age 14 and 15 with bulimia is common these days,Dr. Scheel saiD、
Other people believe the disorders have genetic or chemical components, and many people with eating disorders respond well to anti-depressants, for example.
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A、certain amount of education is necessary to help young people avoid becoming obsessed with their body image. Teachers need to stay outside of talking about diets,"Dr. Scheel saiD、 "It’s like a parent, always talking about their next diet. You have to help a child understand that if you cat healthily and exercise, your body is going to take care of itself."
And in relatively homogenous populations, like in some Westchester schools, competition runs high. "So the young people don’t really see how beautiful diversity is," she said, "and they tend to all be competing for kind of the same goals.\
The studies cited by the NationalEatingDisordersAssociation is based on______.
A、primary school girls
B．secondary school girls
C．girls in college and universities
D．American females in general