CHICAGO - Parents of picky eaters take heart: New research suggests the problem is rarely worth fretting over, although in a small portion of kids it may signal emotional troubles that should be checked.

Preschool-aged children who are extremely selective about what they eat and dislike even being near certain foods are more likely than others to have underlying anxiety or depression, the study found. But only 3 percent of young children studied were that picky.

Less severe pickiness, dubbed "moderate selected eating" in the study, was found in about 18 percent of kids. These are children who will only eat a narrow range of foods. Kids with either level of pickiness were almost two times more likely than others to develop anxiety symptoms within two years, the study found.

More typical pickiness, including kids who just refuse to eat their vegetables, is probably merely "normal dislike," said eating disorders specialist Nancy Zucker, the lead author and an associate psychiatry professor at Duke University's medical school. These are the kids who typically outgrow their pickiness as they mature.

Zucker said young children with moderate pickiness are probably more likely to outgrow the problem than the severe group, although more research is needed to confirm that.

The study was published Monday in the journal Pediatrics.

Dr. Arthur Lavin, a Cleveland pediatrician said picky eating is among the top concerns parents bring to his office, and that the study "helps us understand who we should be concerned about."

"There's more going on here than just not wanting to eat broccoli," said Lavin, a member of an American Academy of Pediatrics committee on psycho-social issues. He was not involved in the research.

The study focused on about 900 children aged 2 through 5 who were recruited from primary care doctors affiliated with Duke's medical center in Durham, N.C.

Researchers did in-home interviews with parents to evaluate kids' eating habits and any mental health issues. Follow-up evaluations were done two years later in almost 200 children.

Compared with children who aren't fussy eaters, depression and social anxiety were at least two times more common in kids with severe pickiness; attention deficit behavior and separation anxiety symptoms were more common in moderately selective kids.

Severe selective eating described in the study is akin to a condition called avoidant/restrictive food intake disorder, added in 2013 to the latest edition of a widely used psychiatric manual, the study authors said. It can occur in all ages; some of those affected are extra-sensitive to food tastes, smells and textures.

Zucker said severe pickiness may be the first clue for parents that a child is experiencing anxiety or depression and that they may want to seek help from a mental health specialist.

Moderate pickiness is less concerning but affected kids can make family meal-times a battleground, she said. To avoid that, Zucker suggests that parents try introducing new foods at random times during the day.