American teenagers who skip breakfast are more likely to be overweight than those who eat a morning meal, according to a study which researchers say may be linked to rising obesity among adolescents.

The five year study showed that those who skipped breakfast were found to weigh about 5lbs (2.3kg) more, ate less healthy during the day and exercised less frequently than those who ate first thing in the morning.

It may seem counter-intuitive, said Mark Pereira, who led the research at the University of Minnesota. But while they ate more calories, they did more to burn those off, and that may be because those who ate breakfast did not feel so lethargic.

Over 2,216 students from Minneapolis and St. Paul middle and high schools contributed to the study by completing diet and weight surveys from 1998 to 1999 and again from 2003 and 2004. Girls were initially more likely than boys to skip breakfast. During the five years, the researchers found an almost 17 percent decrease in the number of boys who ate breakfast.

At the end of the study, 18.9 percent of the boys missed the meal versus 13.8 percent of the girls.

It's not just a girl problem, but it is certainly more of an issue among this group, said Mr Pereira.

They skip breakfast because they worry about weight gain - and it's ironic that the ones who aren't worried and eat in the mornings are the ones who keep their weight down.

According to previous research, 12 to 34 percent of children and teens age 6 to 19 regularly skip breakfast.

The study showed that teenagers who came from low-income homes and were nonwhite were more likely to skip breakfast. Meanwhile, teenagers may have refrained from eating the morning meal to lose weight.

We can't make definitive statements about cause and effect, said Pereira. But the evidence seems to point that way, he added.

What happens is that total fat and saturated fat as a percentage of total daily energy were lower in the breakfast eaters compared with breakfast skippers, Richel explained.

This really shows that we have the potential to improve energy balance and weight control with healthy breakfast consumption. We're not talking pop-tarts.