Monday, February 7, 2011
Previous studies have shown conflicting results on whether the age at which babies start eating solid foods is related to their chance of being obese a few years down the line. Especially among babies who are raised on formula, the transition to solid foods might mean a jump in the amount of calories they are consuming - before parents have learned how much energy their baby really needs.
In the current study, Huh and her colleagues tracked about 850 babies and their mothers over 3 years. When babies were 6 months old, researchers asked the moms whether they had breastfed - and if so, for how long - and when they started feeding their babies solid foods, such as cereal, fruit, and dairy products.
When kids were 3 years old, the researchers measured their height and weight to determine which kids were obese, defined as being in the highest 5 percent of their age and gender for body mass index (BMI), a measure of the relationship between weight and height.
For babies who were breastfed for at least four months, the age that they first received solid food - before 4 months, at 4 or 5 months, or 6 months or later - had no effect on whether they were obese at 3 years. Regardless of when they started eating solid foods, breastfed babies in the study had a one in 14 chance of being obese as preschoolers.
But the findings, published in the journal Pediatrics, were different among babies who were formula-fed from the beginning, or who stopped breastfeeding before they were 4 months old.
Those babies had a one in four chance of being obese at age 3 if they started eating solid foods before they were 4 months old. If parents waited until between 4 and 5 months, the kids' chances of being obese were one in 20.
The chance of being obese increased again if babies didn't start eating solid foods until they were at least 6 months old, but there were too few of those babies for the authors to make a firm conclusion about the risk of waiting longer to feed a baby solid foods.