Keeping slim and trim is fine, but the concept is being carried to extremes by many young girls, who are endangering their health as a result.

A study published in the journal Pediatrics, indicates that many teenage girls, regardless of their weight or knowledge about nutrition, are unwisely bent on losing weight.The journal said a survey of 326 girls between ages of 13 and 18 found that 51 percent of underweight girls were "extremely fearful" of being overweight and 36 percent were "preoccupied with body fat."

About 17 percent of the girls studied were overweight for their height, 47 percent were of normal weight and 36 percent were already underweight, according to researchers from North Shore University Hospital-Cornell University Medical College at Manhasset, N.Y.

Millions of Americans are overweight and find themselves involved in seemingly hopeless programs of trying to lose weight.

That, perhaps, is one reason for the preoccupation of many young women concerned about overeating, gaining too much weight and becoming unattractive.

In addition, there is an emphasis on thinness in society that has nothing to do with health.

Ultra-slender movie and TV actresses or fashion models who are thin to the point of being gaunt are somehow being seen as "normal" or ideal, even though they may represent unhealthy extremes that have nothing to do with real beauty.

If they want to be attractive, teens and young women would be wise to eat well-balanced meals, watching their weight but not getting caught up in fads and an overemphasis on being thin. After all, it is glowing health that is the basis of beauty, not a hollow, emaciated appearance.