What are the best ways to discourage dangerous teen dieting practices? The answers might surprise you. Researchers tracked more than 2,500 adolescents for five years to determine the best things, and worst things, to say to teenagers who are concerned about their weight. Nearly 1 in 5 American adolescents is overweight or obese, but encouraging teenagers to lose weight can be a tricky business.

Adolescents are particularly vulnerable to eating disorders, and so adults must choose their words carefully. New research on more than 2,500 middle and high school students finds one of the best ways to help kids is to eliminate the word "diet" altogether. Telling teenagers to diet often backfires, the study shows.

Adolescents who are self conscious about their weight are more likely to turn to dangerous behaviors such as taking diet pills, skipping meals, or self-induced vomiting. Researchers suggest doctors tell young patients that extreme dieting can actually add pounds to discourage them from trying these practices.

Teenagers with poor body image gained the most weight in the study, so experts say parents should not criticize their children's weight. Instead, families should focus on healthy eating and enjoying physical activities together, such as bike riding or ball games in the backyard.