Kids who have food allergies or are overweight may be especially likely to get bullied by their peers, two new studies suggest.

Not surprisingly, researchers also found targets of bullying were more distressed and anxious and had a worse quality of life, in general, than those who weren't picked on.

Bullying has become a concern among parents, doctors and school administrators since research and news stories emerged linking bullying - including online "cyberbullying" - with depression and even suicide.

"There has been a shift and people are more and more recognizing that bullying has real consequences, it's not just something to be making jokes about," said Dr Mark Schuster, chief of general pediatrics at Boston Children's Hospital and a professor at Harvard Medical School, who wrote a commentary published with the new research.

Studies suggest between one in 10 and one in three of all kids and teens are bullied - but those figures may vary by location and demographics, researchers noted.

The new findings come from studies published Monday in the journal Pediatrics.

In one study, Dr Eyal Shemesh from the Mount Sinai Medical Center in New York and his colleagues surveyed 251 kids who were seen at an allergy clinic and their parents. The children were all between age eight and 17 with a diagnosed food allergy.

Just over 45 percent said they'd been bullied or harassed for any reason, and 32 percent reported being bullied because of their allergy in particular.

"Our finding is entirely consistently with what you find with children with a disability," Shemesh told Reuters Health.

A food allergy, he said, "is a vulnerability that can be very easily exploited, so of course it will be exploited."

The kids in the study were mostly white and well-off, the researcher said - a group that you'd expect would be targeted less often. So bullying may be more common in poorer and minority children who also have food allergies.

But allergies aren't the only cause of teasing and harassment by peers.

In another study, researchers from Yale University in New Haven, Connecticut, found that almost two-thirds of 361 teens enrolled in weight-loss camps had been bullied.

That likelihood increased with weight, so that the heaviest kids had almost a 100 percent chance of being bullied, Rebecca Puhl and her colleagues found. Verbal teasing was the most common form of bullying, but more than half of bullied kids reported getting taunted online or through texts and e-mails as well.

"Kids need their parents to be their allies in these situations," he said. "Their parents can help them still feel strong."

Reuters