MINNEAPOLIS (US): For parents concerned about their overweight teens, new research suggests the best tactic might be to just relax and cook a healthy Sunday dinner.

Pushing diets probably won't help. Neither will teasing about weight. Instead parents should focus on having frequent family meals, creating a positive atmosphere at mealtimes, promoting physical activity and building self-esteem, the researchers recommend.

The study of more than 2,500 adolescents over five years reinforced several things that doctors have found among their patients -- particularly that destructive behaviours such as vomiting or abusing laxatives are prevalent among overweight teens as well as their too-thin peers, and that body attitudes and perceptions can play a big role in future weight problems.

"This is obviously of concern," Dianne Neumark-Sztainer, lead author of the study at the University of Minnesota, said of the risky behaviors. "We know that these behaviours tend to actually increase weight gain over time. It points to a need to address these behaviours with overweight kids."

The research will be published in the November issue of American Journal of Preventive Medicine.

The study found that 44 per cent of the girls and 20 per cent of the boys were either overweight, engaged in binge eating or had used extreme weight-control measures -- such as purging or abusing laxatives, diet pills or diuretics.

Of the overweight adolescents, about one fourth of the girls reported using extreme measures, while 10 per cent reported using extreme measures as well as binge eating. Only about 12 per cent of overweight boys used extreme measures.