Genes may contribute to childhood obesity, study says

LOS ANGELES (KABC) -- In the past 30 years, childhood obesity has more than doubled in children and tripled in adolescents. New research reveals this is a trend that may start during the first few months of a baby's life.

A quick weigh-in and measurement tells Pediatrician Dr. Marsha Gerro how much 4-month-old Alexandra Antonucci has grown. But something else Alexandra does may tell her mom, Celeste Antonucci, what her long term risk for obesity might be.

"Oh, she eats all the time," said Celeste, "I read that most babies will eat every two hours during the day, but pretty much when she gets up, it's every hour."

A hearty appetite is usually considered a good thing, but new research reveals a connection between an infant's early response to food and future weight gain.

A second study in the Journal of the American Medical Association Pediatrics also finds genetics plays a role in how quickly an infant feels full or satiety - another early marker that may predispose a child to obesity.

"I think that studies would show that children who get excessive calories will develop more fat cells in infancy," said Gerro.

She says knowing these clues can help parents, and just because a baby cries doesn't mean they are always hungry.

"I would want to tell them how to soothe their babies in other ways like maybe change the baby's position, maybe offer the baby a pacifier, try carrying the baby, taking the baby outside," said Gerro.

The 50th percentile is considered the ideal range. A little above and a little below is still considered healthy, but there are other things that doctors take into account when considering your child's weight.

"I would say, basically, parents should consult their doctors and not worry too much," said Gerro. "We don't expect every baby to be in the 50th percentile. We don't, we expect there's going to be a spread."

Alexandra is right at the 40th percentile. Keeping an eye on her, how hungry she gets and how long she stays full are two more items to add to the list of things her parents need to keep track of.

Study authors say their findings confirm why genetics play such a big role in overeating, so they conclude more strategies should be targeted at getting kids to understand when they should feel full.