April 6 (HealthDay News) -- Small children who can't keep their hands out of the cookie jar -- in other words, those who have more difficulty delaying gratification -- appear more likely to be overweight as they get older.
The same seems true of young children who are unable to stay away from enticing toys.
It's unclear whether these findings, from two studies published in the April issue of Archives of Pediatrics & Adolescent Medicine, represent a "nature" or "nurture" effect, yet they could still result in positive behavioral changes to help stem the current obesity epidemic, experts said.
"There are so few studies that track obesity development over time, so the fact that they were able to capture something early in obesity development and track it over time into middle childhood is rare," said Meg H. Zeller, assistant professor of pediatrics at Cincinnati Children's Hospital.
"The fact that it's something behavioral is one of the highlights, because it gives you something to work with. You've identified something that is modifiable," added Zeller, who was not involved with the studies.
Previous studies have linked adult weight problems -- and accompanying problems such as heart disease and diabetes -- with weight issues earlier in life, although few had looked at a possible association with the ability to delay gratification.
For the new study, 805 children 4 years old were put in a room by themselves with one large plate and one small plate of candy, animal crackers or pretzels. They were told they could eat the larger plate if they waited for an adult to return. If they couldn't wait, they could ring a bill to summon the adult.
Forty-seven percent of the participants "failed" the test either by ringing the bell or by just jumping into the goodies.
Those who failed were 29 percent more likely to be overweight seven years later, at age 11. They were also more likely to have mothers who were overweight, which could reflect both genetic and environmental factors, the researchers stated.
The second study found similar results in a sample of 1,061 children who were 3 years old -- both with toys and, two years later, at age 5, with food.
Like the first study, the children were asked to sit alone in a room with a toy for 150 seconds. If they waited at least 75 seconds to play with the toy, they "passed the test." At 5 years old, they participated in a similar food test.
Those who weren't able to wait in both scenarios had a higher body mass index (BMI, a ratio of weight to height) at age 12 and gained weight faster.
But it's not clear if the delayed gratification response actually caused the weight issues; nor is it clear if this is a nature or nurture issue.
"We don't know if it's parenting or something innate to the kid," said Dr. Julie C. Lumeng, lead author of the food study and an assistant professor of pediatrics at the University of Michigan Medical School.
It's possible, she added, that many children, like many adults, are using food to regulate mood.
Despite unanswered questions, the findings could have some immediate impact.
"If you have a child that has difficulty delaying gratification, you could help that child learn those skills," said Lumeng, an assistant research scientist at the university's Center for Human Growth and Development.
One strategy would be to put food in the cupboard, "out of sight and out of mind." Or distract a child who keeps asking for the food, or even eliminate junk food from the house entirely.
Structured snack and meal times may also help, Lumeng said.
"This really gives people who are looking at obesity prevention, which is so critical at this time, something to develop an intervention around," Zeller added. "Pediatricians can do it, and parents understand the idea of delaying gratification. We live in such an immediate gratification environment."
SOURCES: Julie C. Lumeng, M.D., assistant professor of pediatrics, University of Michigan Medical School, and assistant research scientist, Center for Human Growth and Development, University of Michigan, Ann Arbor; Meg H. Zeller, Ph.D., assistant professor of pediatrics, Cincinnati Children's Hospital; April 2009, Archives of Pediatrics & Adolescent Medicine