"Choosing a lifestyle that's sustainable and healthy - where the fuel intake matches the output - is really the safest long-term plan for weight management," Liechty said.

"Even though excessive exercise or exercise addiction can become a problem for a small percentage of people, staying physically active is an important ingredient of lifetime weight management. But if we exercise out of addiction or a punitive attitude toward our bodies, it's associated with depression and anxiety. So the attitude and the relationship with self and with body matter a lot in how we approach taking care of ourselves."

Liechty says her findings underscore the urgency for prevention efforts that foster positive and accurate body-image among adolescent girls.

"The best method of weight control is to focus on lifestyle changes and not on radical approaches, because extreme methods wreak havoc with our body chemistry as well as our attitude toward food and toward our bodies," Liechty said.

Dieting, especially what Liechty calls "teenage-style dieting," and extreme weight-loss methods can be risky business.

"They tend to be all-or-nothing, which often leads to cycles of restricting and bingeing. Ironically, other research has shown that this type of dieting among children and teens usually leads to weight gain later in life."

Learning healthy weight-loss and maintenance behaviors is important because bad habits can be addictive, leading to lifelong struggles with eating, Liechty said.

Overweight teens who desire to lose weight need support and a sensible, sustainable plan, Liechty says.

"Parents can encourage healthy eating and exercise habits from the start by leading by example, but if teens want to lose weight, parents should take them to the doctor or health-care professional and discuss how much they should lose, at what pace, and how to do it safely in a careful, planned way," she said.

If teens don't need to lose weight, they should avoid fad diets, ignore quick weight-loss promises, and not get sucked into trying extreme methods like diet pills and purging.

"The underlying issue is our relationship with food and our bodies," Liechty said. "A distorted view of one's weight status makes one more vulnerable to using unsafe weight-loss behaviors. The key is to cultivate a positive, realistic, and appreciative relationship with your body regardless of your weight, then get support to develop eating and activity habits that balance input and output, and that you can live with for long time."

Source: University of Illinois at Urbana-Champaign