Remember that time in third grade when you called the pudgy boy in gym class "fatso?"

It wasn't just mean. It might have inflicted lasting wounds, according to a Yale University study released yesterday that found that overweight and obese children who are subjected to verbal taunts and physical bullying are substantially more prone during childhood to suicidal thoughts, eating disorders, and high blood pressure than their peers.

Yale clinical psychologist Rebecca M. Puhl and a colleague from the University of Hawaii at Manoa reviewed four decades' worth of psychological, social and medical research on childhood obesity -- more than 100 studies. They discovered that taunts, shoves, and social isolation can wreak emotional and physical harm in childhood and possibly beyond that is distinct from the health consequences of being overweight.

"It's important to distinguish that it's the victimization and the teasing that are leading to these consequences," Puhl said, "and not the obesity itself."

The research, which appears in the July issue of the Psychological Bulletin, also found that the discrimination by children against their overweight peers is breathtaking.

One widely cited 1961 study, replicated 42 years later, asked 10- and 11-year-olds to look at six pictures of other youngsters and rank the order in which they would like to be friends with them. The pictures depicted a child in a wheelchair, one on crutches, another with an amputated hand, a fourth with a facial disfigurement. A fifth photo showed an average-weight child with no disabilities and a sixth showed an overweight youngster.

In both the 1961 study and the 2003 follow-up, the heavy child was resoundingly sixth in order of preference, and spurning of the overweight child was more extreme in the more recent study. Overweight children are regarded with disdain, branded as lazy, ugly, stupid, and sloppy -- with the bias that they should be able to do something about the extra weight.

"There's a high cost for obesity, and it's not just around the physical challenges," said Dr. Nancy Rappaport , director of school programs at Cambridge Health Alliance . "It's also around the corrosive undermining of self-confidence and the ability to see the possibility for change."

The taunts -- and the damage -- appear to be most pronounced among the heaviest children. But the stigma isn't limited to youngsters who are significantly overweight; even children who are just a little bit heavy are subject to teasing, the researchers found.

Too often, specialists said, the teasing begins in the one place that should provide a sanctuary from harm: the home.

Yesterday's study, for example, recounted a survey of 4,746 adolescents. About 47 percent of very overweight girls and 34 percent of the very overweight boys said they had been frequently teased about their weight by family members.

"There's a lot of teasing that goes on in the house, with some parents even who call their children 'fat' or 'pig,' " said Dr. Carine Lenders , medical director of the children's nutrition program at Boston Medical Center .

Overweight adolescent girls and boys who endure frequent episodes of teasing are more likely to engage in unhealthy eating habits, including binging, than equally overweight adolescents who aren't the target of taunts. Obese adolescents who experience bias are two to three times more likely to contemplate suicide than obese teens not victimized by teasing.

And a 2005 study cited in yesterday's report found that taunting was the most likely cause of higher blood pressure in overweight adolescents, even after taking into account an array of other factors, including weight, race, and physical activity.

Data from the US Centers for Disease Control and Prevention show that children have grown significantly fatter in the past three decades. Among 6- to 11-year-olds, for instance, the percentage of children who are overweight climbed from 6.5 percent in the mid-1970s to 18.8 percent in 2003 and '04.

At the same time, specialists said, American society is more obsessed than ever with idealized images of wafer-thin celebrities, a phenomenon that may be fueling the impulse to ridicule.

"We live in a society that is extraordinarily weight conscious," said Dr. David Ludwig , an obesity specialist at Children's Hospital Boston .

Ludwig and other specialists said that before designing a regimen to help children shed pounds, it's imperative that children and parents address teasing, and acknowledge in a straightforward fashion that the child is, in fact, overweight.

Paradoxically, taunting appears to discourage heavy children from getting exercise , according to studies and physicians.

"A lot of children, because of the teasing, refuse then to go swimming -- they don't want to put a swimming suit on," Lenders said. "A lot of children prefer to stay home, watch TV, and not interact with their peers."