Children and teens who reported overeating, including binge eating, were more likely to start using marijuana and other drugs, according to a US study looking at over 10,000 youths.
Binge eating, defined by loss of control during overeating, was also tied to a higher chance of depression and becoming overweight or obese, researchers writing in the Archives of Pediatrics & Adolescent Medicine said.
"Physicians and parents should be aware that both overeating and binge eating are quite common in adolescents, and these problems put them at risk for other problems, such as drug use," said lead author Kendrin Sonneville, from Boston Children's Hospital.
"The earlier we can screen for who is at risk, the more able we are to prevent the onset of drug use."
This type of study does not prove that one behaviour causes another, but rather that one can be a warning sign of increased risk for the other.
Sonneville's team used data from a large study of 16,882 children and teens, initially between age nine and 15, who filled out health-related questionnaires every year or two between 1996 and 2005.
At any point during that time, up to one per cent of boys and up to three per cent of girls said they binged regularly. Those rates were reversed - about three per cent of boys and one per cent of girls - among children who overate without loss of control.
During the study period, 41 per cent of youths started using marijuana and 32 per cent used other illicit drugs. Children and teens who had reported overeating on surveys were 2.7 times more likely to start using marijuana or other drugs, and binge eaters were 1.9 times more likely to take up drugs.
Researchers have thought teens who lose control while eating might also be at risk for other impulsive behaviours, such as drug use, Sonneville said. But her findings showed that any kids who overate - whether they reported losing control or not - were more likely to start experimenting with drugs.
It's not yet clear why that might be the case.
Overeating without loss of control wasn't tied to obesity, so it's important to know that eating too much can be a problem for reasons other than weight, Sonneville said, and that extra weight isn't the only sign of worrisome eating.
She said doctors should ask children and teens about their eating patterns, and parents who notice their children eating much more than usual in a sitting should go to their health care provider. Treatment from a dietician or therapist could help head off future problems, she added.
"It may be easy to overlook eating problems in normal-weight or healthy-weight kids," she said. "We need to think about eating habits even before they maybe affect a kid's weight, but realise these may be a risk factor for other problems down the road."