Babies who grow too fast have a much higher risk of becoming obese, a study indicates.
Babies who grow too fast have a much higher risk of becoming obese, a study indicates. (Los Angeles Times)


Infant weight and height are faithfully charted at each pediatrician's visit to make sure the child is growing properly. But nowadays doctors are more likely to see babies who are growing too fast rather than ones lagging behind. A new study shows that rapid growth on these charts foretells obesity in childhood.

Researchers looked at the weight-for-length charts that show how a baby's weight compares to that of other babies of the same length. For example, babies on the 5th percentile growth line have a weight that puts them among the smallest 5% of all babies their length. Doctors mostly want to see that a child is following his or her growth curve over time and not falling off or jumping up. The major percentile lines are the 5th, 10th, 25th, 50th, 75th, 90th and 95th.

The study, which tracked more than 44,000 babies, found that those who rose two or more major percentiles -- for example, going from 50% to 90% at some point -- before age 2 were twice as likely to be obese at age 5 and 75% more likely to be obese at age 10.

Babies who jumped two or more percentiles before six months of age had the highest risk of obesity at age 10 as well as babies who were already in a high percentile at their first visit. For example a 6-month-old baby who started at the 75th percentile who jumped two or more percentiles in the next six months had an obesity prevalence of almost 30% at age 5. Babies who started at less than the 25th percentile and jumped two or more percentiles had an obesity prevalence at age 5 of about 7%.

"We shouldn't neglect these early gains and think that it's just baby fat, and that these children are going to grow out of it," said Dr. Elsie Taveras, the lead author of the study at Children's Hospital Boston.

Of all the babies in the study, 11.6% were obese at age 5 and 16% at age 10. Jumping two or more percentiles was common, the researchers found, with 43% rising two or more percentiles in their first six months of life and 64% at some point in their first two years.

The study was published Monday in the Archives of Pediatrics and Adolescent Medicine. The journal also carries an interesting commentary on child obesity by Dr. Robert C. Whitaker of the Center for Obesity Research and Education at Temple University.

Whitaker discusses the widespread social change that will be required to reverse the obesity epidemic. "The childhood obesity epidemic was an unexpected consequence of numerous well-intentioned decisions made by adults about how to improve our way of living. These decisions were often made without considering children or all aspects of their well-being," he writes.

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