“Look at those cute little rolls of fat and chubby cheeks.” “It’s just baby-fat, he’ll grow out of it.” Common comments when people see a chubby baby. But, what was once thought of as a well-fed and healthy infant might prove to be just the opposite.
Researchers say they’ve found a way to determine if a rapid growing baby will become obese later in life. A new study says that if your baby has passed two key milestones, on a doctor’s growth chart by the age of two, then he or she has double the risk of being obese by the age of 5. Rapid growers were also more likely to be obese at age 10, and infants whose chart numbers climbed that much during their first 6 months faced the greatest risks.
Children who grew more slowly were less likely to be obese by the same age.
That kind of rapid growth should be a red flag to doctors, and a sign to parents that babies might be overfed or spending too much time in strollers and not enough crawling around, said pediatrician Dr. Elsie Taveras, the study's lead author and an obesity researcher at Harvard Medical School.
Contrary to the idea that chubby babies are the picture of health, the study bolsters evidence that "bigger is not better" in infants, she said.
In an online article on healthland.time.com Dr. Michelle Lampl, director of Emory University's Center for the Study of Human Health, expressed concerns.
“It’s a bad idea that could backfire in the long run,” said Lampl.
"It reads like a very handy rule and sounds like it would be very useful _ and that's my concern," Lampl said. The guide would be easy to use to justify feeding infants less and to unfairly label them as fat. It could also prompt feeding patterns that could lead to obesity later, she said.
Lampl noted that many infants studied crossed at least two key points on growth charts; yet only 12 percent were obese at age 5 and slightly more at age 10. Nationally, about 10 percent of preschool-aged children are obese, versus about 19 percent of those aged 6 to 11.
Taveras said the rapid growth shown in the study should be used to raise awareness and not to put babies on a diet.
The study involved 45,000 infants and children younger than age 11 who had routine growth measurements during doctor checkups in the Boston area from 1980 through 2008.
Growth charts help pediatricians plot weight, length in babies and height in older kids in relation to other children their same age and sex. Pediatricians sometimes combine an infant's measures to calculate weight-for-length _ the equivalent of body-mass index, or BMI, a height-to-weight ratio used in older children and adults.
The charts are organized into percentiles. For example, infants at the 75th percentile for weight are heavier than 75 percent of their peers.
An infant whose weight-for-length jumped from the 19th percentile at 1 month to the 77th at 6 months crossed three major percentiles _ the 25th, 50th and 75th _ and would be at risk for obesity later in childhood, the authors said.
Larger infants were most at risk for obesity later on, but even smaller babies whose growth crossed at least two percentiles were at greater risk than those who grew more slowly.
About 40 percent of infants crossed at least two percentiles by age 6 months. An analysis of more than one-third of the study children found that 64 percent grew that rapidly by age 2.
Dr. Joanna Lewis, a pediatrician at Advocate Lutheran General Hospital in Park Ridge, Ill., said she supports the idea that infancy is not too young to start thinking about obesity.
Still, she emphasized that rapid growth in infancy doesn't mean babies are doomed to become obese. "It's not a life sentence," and there are steps parents can take to keep their babies at a healthy weight without restrictive diets, she said.
Lewis said many of her patients are large babies whose parents feed them juice or solid food despite guidelines recommending nothing but breast milk or formula in the first six months.
"The study reinforces what we try to tell parents already: Delay starting solids and don't put juice in a bottle," Lewis said.