RENEE MONTAGNE, host:
Obesity in an older child or an adolescent is pretty easy to diagnose. NPR's Deborah Franklin talks to a pediatric expert about when parents should be concerned about a pudgy baby.
DEBORAH FRANKLIN: Infants are the ultimate couch potatoes - cooing, dimpled eating machines. But can a baby be too fat? Matthew Gillman is a pediatrician at Harvard. He says yes.
Dr. MATTHEW GILLMAN (Pediatrician, Harvard University): Excess or accelerated weight gain even in the first four or six months of life may be setting up kids for overweight, for higher blood pressure, maybe even for asthma over the first years in childhood.
FRANKLIN: Gillman's been tracking the vital statistics of well-fed babies and toddlers born and raised in eastern Massachusetts over the last 22 years. He insists he's got nothing against pot-bellied infants.
Dr. GILLMAN: Well, I was a pretty chubby baby myself.
FRANKLIN: Still, as a doctor, Gillman's worried. His research suggests that the percentage of children under age 2 who top the weight charts is creeping higher with every generation. He says there are a bunch of reasons for that, and some on the list might surprise you.
For example, if a mother smokes during pregnancy, she's at risk of having an extra-small newborn who then grows up to be an overweight child. Also, Gillman says that in his study, babies who didn't get enough sleep tended to pack on unneeded ounces that soon added up to unneeded pounds.
Dr. GILLMAN: Kids who got less than 11 hours of sleep were at more than 50 percent higher risk for developing overweight by the age of 3, compared with those infants who slept more than 13 hours a day.
FRANKLIN: So what's the parent of a chubby tot to do? Don't start counting double chins.
Dr. GILLMAN: All babies have their baby fat until they get to 3 or 4 or 5 years old. So it really is important to get an accurate weight and especially length measure so that we can see where it falls on the growth chart. And that's how we compare your child with every other of the same sex and age.
FRANKLIN: Gillman says it doesn't pay to cut back on the child's calories and fat too soon. Cells, especially those that surround budding brain cells, need fat to support and nurture them. He says that's one of the reasons the American Academy of Pediatrics recommends that even after children switch from breast milk to cow's milk, they should continue drinking whole milk until they're 2 or so, and only then switch to nonfat or one percent milk.
The best way to keep tabs on whether or not your baby's weight is within normal bounds is to check in frequently with a pediatrician. The doctor has the experience to be able to keep an eye on overall trends in the child's growth.
Dr. GILLMAN: If they're gaining weight very fast, that would be a key sign for later overweight, and that might be a warning sign for both parents and pediatricians.
FRANKLIN: The bottom line: Putting on pounds quickly is normal for a baby, but putting on too many, too quickly, is not. And it can take an expert's eye to know the difference.
Deborah Franklin, NPR News.
MONTAGNE: And if you have questions for our experts on weight problems in infants and children, you can send them to us through our Web site: NPR.org/yourhealth.
You're listening to MORNING EDITION from NPR News.