The stigma that society attaches to obesity can cause children immediate, and possibly lasting, harm, according to a research review.

Overweight children and teens are commonly teased or ostracized by their peers, and sometimes treated differently by teachers and even parents. This, the review shows, can lead to low self-esteem, poor school performance, avoidance of physical activity and, in the most serious cases, depression and suicide.

Research has long demonstrated the weight bias that heavy children face. In a classic 1961 study, 640 subjects between 10 and 11 years old were shown six pictures of other children their age: one child was overweight; one was normal-weight; and four had some form of physical disability.

When the study participants were asked to rank the children in the order of whom they would like to be friends with, they ranked the overweight child last.

Many studies since then have confirmed the extent of weight bias among children and adults alike, according to the review, published in the journal Psychological Bulletin.

Some studies found that a sizable number of teachers harbor negative views of overweight students, seeing them as "untidy," for example, or less likely to succeed than their thinner peers. Other research found that overweight children often report teasing from family members, including parents.

Much less is known about the long-term consequences of such weight bias. But studies show that victimized children and teens have higher risks of eating disorders, suicidal thoughts, and physical health problems, such as high blood pressure, the review found.

They may also avoid exercise because of teasing, which could increase their odds of diabetes and heart disease down the road.

All of this means that weight teasing needs to be taken seriously, study co-author Rebecca M. Puhl told Reuters Health.

For parents, it's important to listen to their children's concerns and help them find ways to cope with teasing, said Puhl, a researcher at the Rudd Center for Food Policy & Obesity at Yale University in New Haven, Connecticut.

Parents should also be aware of how their own attitudes and comments -- including critical remarks about their own bodies -- shape their children's self-esteem, Puhl noted.

With the rate of childhood obesity growing, it's important that obesity prevention efforts do not increase the stigma attached to being overweight, according to Puhl.

This means that parents, as well as school programs, should focus on the benefits of healthy eating and exercise, and not on attaining a certain body shape.

"Messages about weight that are delivered to children must be done in a careful and sensitive manner," Puhl said.