Pre-teens feel pressure to have a perfect body, suggests a new study, which found that satisfaction with their body shape was directly linked to their weight.

In a study of more than 4,200 schoolchildren from Nova Scotia, researchers from Harvard University and the University of Alberta found that girls were happiest when they were thinnest and boys were unhappy when they were too skinny or too fat.

For their study, the researchers measured the height and weight of their 10- and 11-year-old subjects, and then asked them how much they agree with the statement, "I like the way I look."

Overall, 7.3 per cent of girls and 7.8 per cent of boys said they had poor body satisfaction.

Among girls, poor body satisfaction was at 5.7 per cent for those of normal weight, 10.4 per cent for those who were overweight and 13.1 per cent for those who were obese.

Among boys, poor body satisfaction was at 7.6 per cent for those of normal weight, 8.4 per cent for those who were overweight and 8.1 per cent for those who were obese.

In the study, lead researcher Bryn Austin explained that poor body satisfaction among boys of normal weight "may reflect the cultural ideal for males to attain both muscularity and leanness; whereas, among females, thinness remains the culturally defined ideal body shape."

Researcher Paul Veugelers, of the University of Alberta, said poor body satisfaction puts youth at higher risk of unhealthy, and potentially dangerous, behaviours.

"Body satisfaction is generally seen as an early indicator of disordered behaviour," Veugelers told CTV News. "People who have concerns about their body satisfaction, body image, are at risk to go fasting, self-induced vomiting, to use laxatives, to use diet pills and that is all then on a trajectory to bulimia, binge eating and anorexia."

Researchers were shocked to find that children so young were already struggling with their body image, Veugelers said.

"The kids at this young age should not be worried about the way they look, they should just play and have fun and learn," Veugelers said.

According to Veugelers, the food industry and the media propagate mixed messages that can lead to poor body image and unhealthy behaviours.

"On the one side there's the food industry telling us, 'Eat more, more, more," and on the other side there's the media and the fashion industry and the cosmetic industry saying, 'You have to look slim, slim, slim.' So there's a pressure and that causes that disordered behaviour."

Toronto teen Jade Regina also blames images in magazines and on television shows that display difficult-to-attain body types. Regina said she has teenaged friends that have gym memberships and have already tried various diets.

"It's pretty sad because if you don't fit in you get excluded and made to feel bad -- just put down," Regina, 15, told CTV News. "(With) all the magazines and TV shows these days, you have to try and look perfect, you know? It's really sad."

The research team also studied how body satisfaction might be influenced by socioeconomic factors.

The results showed that girls who lived in rural areas and whose parents who did not pursue higher education were more likely to report poor body satisfaction.

"Our finding that girls who reside in rural areas, controlling for (body mass index), are more likely to report poor body satisfaction suggests that appearance-related pressures may be higher within rural areas," Austin speculated. "Or perhaps that girls in urban areas benefit from existing programs that may protect against decrements in body satisfaction."

The findings are published in the open-access journal BMC Public Health.

According to the study, as many as 26 per cent of children between the ages of six and 11 in Canada, and 33 per cent of U.S. children in the same age group, are overweight.

In their study, the researchers suggest that anti-obesity campaigns may be more successful if they tapped into body satisfaction to promote healthy eating habits and exercise.

Minnesota-based research, dubbed Project EAT, found that greater body satisfaction at the beginning of the study, when subjects were in junior and senior high school, was associated with healthier eating and exercise habits five years later. Subjects were also less likely to be overweight in five years if they had greater body satisfaction at the study's start.

Michelle Brownrigg of Active Kids Canada said the age group studied in the Harvard/UofA research is the time when children start to become less physically active and, as a result, lose some of their self-esteem.

Brownrigg said the study's findings demonstrate the importance of teaching children how to gain confidence in their bodies by eating well and getting enough physical activity.

"We have to give kids positive messaging, through other media, that focuses on how to feel good about yourself and your bodies, with the way you use it, what you eat or what your activities are," Brownrigg told CTV News.

With a report from CTV medical correspondent Avis Favaro and producer Elizabeth St. Philip