TORONTO - Childhood obesity can increase the risk of developing low self-esteem in the tween and teen years, a new study from Statistics Canada suggests.

Chief analyst Julie Bernier says a lot of attention has been paid to being overweight and obese as precursors to developing physical health problems such as Type 2 diabetes or cardiovascular problems.

But this report takes a rare look at body weight vis-a-vis self-esteem in childhood. Previous studies have found that low self-esteem as a youngster can predict poor mental health in adulthood.

"It's certainly important to know what are the determinants of potential health problems later," Bernier said from Ottawa.

"Up to now in the literature, there has been a lot of emphasis on the fact that body weight problems could lead to a lot of chronic disease ... and now, it's a complement to see that it even puts you more at risk for low self-esteem, which in turn would put you at risk for mental health problems."

The study by researchers at the University of Alberta relied on Statistics Canada data from the mid-to late-'90s, specifically the first three cycles of the Canadian National Longitudinal Survey of Children and Youth.

Kids at the ages of 10 and 11 completed a four-item scale that assessed their overall self-esteem, rating statements such as "In general, I like the way I am" and "Overall I have a lot to be proud of."

They were surveyed twice more, two years and four years later. Assessments about whether someone was overweight or obese were derived from height and weight measurements reported by the person most knowledgeable about the child, such as a parent or guardian.

Researchers who studied the data found that children who were obese in the beginning had almost twice the odds of reporting low self-esteem four years later, compared with normal weight children.

Bernier explained that it's been known for some time that there's a relationship between body weight and self-esteem.

"But we also know that there's other things that are related to self-esteem, like your school performance, your parental education, your weekly physical activity, your weekly time spent in front of a screen and stuff like that," she said.

"So we first looked at the relationship between body weight and self-esteem, but controlling for all those other potential confounding factors. And what we find for the 10-to 11-year-olds is that there is a relationship between self-esteem and body mass index, even when you take everything into account."

The second part of the study involved looking for a pattern: "Is it your body mass index that would be a predictor of your self-esteem in the future, or is it your self-esteem that would be a predictor of your body mass index?"

They found that body weight is a predictor of self-esteem - not the other way around.

Bernier said it's important to study these issues to figure out what preventative actions to take.

"It's pretty clear that you have to intervene when there's a weight problem," she said.

The study also found that physical activity and gender were statistically significant predictors of low self-esteem.

Kids taking part in physical activity five to seven times per week were less likely than children participating twice or less per week to have low self-esteem four years later, the study found.

"It reinforces the fact that it's important for kids to do physical activity," Bernier said.

Boys were less likely than girls to have low self-esteem four years after their initial questionnaire.

An estimated one in four Canadian children and youth are overweight or obese.

"The current childhood obesity epidemic may trigger an increase in the population prevalence of low self-esteem in the future," the study warned.

Also Wednesday, research to reduce childhood obesity received $1.9 milllion in new funding. The grants were announced by the Canadian Institutes of Health Research, the Rx&D Health Research Foundation, the Heart and Stroke Foundation of Canada, and the First Nations and Inuit Health Branch of Health Canada.

The projects include a study of how family, peers and school environments affect the attempts of overweight adolescents to lose weight, as well as a web-based survey of diet and physical activity among Cree schoolchildren in the Hudson and James Bay regions.