Playing the Odds on Children's Weight Gain

Child risks of being overweight are influenced by multiple factors

(RxWiki News) The talk about rates of childhood obesity in the US is hard to ignore. But all that talk isn't helpful unless parents have information about what puts a child at a higher risk for becoming obese.

A recent study looked for risk factors that influence a child's likelihood of being overweight at age 3.

The researchers found seven characteristics. Not all of them are things parents can change, but several of them are.

The parents' own weights and whether a child is breastfed and/or exposed to smoke before birth are among the factors that might make a difference in their weight.

"Ask a pediatrician about your child's weight."

This study, led by Stephen F. Weng, MPH, of the School of Community Health Sciences at the University of Nottingham in the United Kingdom, looked for the primary risk factors for childhood obesity.

The researchers analyzed data from an ongoing long-term study that involved 13,513 children, aged 6 months to 12 months when their parents were first interviewed.

At 3 years old, 23 percent of the children were overweight, and the average body mass index (BMI) of the whole group was 16.85.

BMI is a ratio of a person's height to weight and is used to determine whether they are a healthy weight.

Being overweight was defined as a child having a body mass index (BMI) greater than 18 for girls or 18.4 for boys.

The researchers found that out of 33 possible characteristics, seven were linked to children being overweight at age 3.

These factors included the child's gender, birth weight and early weight gain. The factors also included whether the mother breastfed the child, whether the mother smoked during pregnancy, what the mother's weight was before pregnancy and what the father's weight was.

The importance of each of these factors in influencing a child's risk of being overweight varied greatly.

Girls were about 15 percent more likely to be overweight than boys. Babies who were in the top 20 percent for their birth weight were about 63 percent more likely to be overweight than babies in the lowest 20 percent.

Babies who rapidly gained weight during their first year were four times more likely to be overweight at age 3 than babies who grew at an average rate.

Children of mothers who smoked during pregnancy were 33 percent more likely to be overweight than children of mothers who didn't smoke during pregnancy.

Children who were never breastfed during their first year were 25 percent more likely to be overweight than breastfed children.

The weight of the children's parents made a difference in the child's overweight risk as well.

Compared to children of mothers who were underweight before pregnancy, children were three times more likely to be overweight if their mothers were overweight before becoming pregnant.

Similarly, children of obese fathers were twice as likely as children of underweight fathers to be overweight.

Not all of these risk factors are things that parents can change. However, parents can make decisions about smoking during pregnancy or healthier nutritional decisions that may influence their own weight.

Knowing the factors that can influence a child's risk of becoming overweight may help parents in their efforts to prevent future obesity in their children.

This research was published July 15 in the journal Pediatrics.

The research was funded by the National Institute for Health Research Collaboration for Leadership in Applied Health Research and Care — Nottinghamshire, Derbyshire and Lincolnshire. The authors declared no conflicts of interest.

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Review Date: 
July 12, 2013