Many adolescent girls try to control their weight in ways that may leave them deficient in calcium, iron and other essential nutrients, a new study of more than 4,100 students at Minnesota middle schools suggests.

The study found that 57 percent of girls were using at least one unhealthy approach to weight loss, including fasting, skipping meals, smoking, or using laxatives, diet pills or diuretics.

What's more, compared with their peers who weren't trying to control their weight, dieting girls ate fewer fruits, vegetables and grains, and had lower intakes of calcium, iron and several vitamins. In general, the girls had poorer diets compared with girls who weren't trying to control their weight and those who were using healthy means, such as increasing fruit and vegetable intake, cutting down on sweets, and exercising.

Children and teens, like adults, need to learn to follow a healthy lifestyle that includes regular exercise and plenty of fruits, vegetables and low-fat dairy products, according to the lead researcher from the University of Minnesota School of Public Health in Minneapolis. And one key way for them to learn that is for parents to set an example by eating well and exercising.

Parents need to support children by buying healthful foods and encouraging physical activity.

The study included 4,144 public school students who answered questions on their diets and whether they used any number of weight-control tactics, some healthy, some not. Nearly 88 percent of girls said they were trying to lose or maintain their weight, more often than not by unhealthy means. The fact that so many girls were worried about their weight is another concerning finding.

The findings for boys painted a much more puzzling picture. Nearly one third said they'd tried to control their weight in an unhealthy manner, but these boys did not show the nutritional consequences that girls did. In fact, they had the highest fruit intake of all the boys in the study. In general, boys trying to control their weight, whether through healthy or unhealthy means, had higher-quality diets.

All research on this web site is the property of Leslie Beck Nutrition Consulting Inc. and is protected by copyright. Keep in mind that research on these matters continues daily and is subject to change. The information presented is not intended as a substitute for medical treatment. It is intended to provide ongoing support of your healthy lifestyle practices.