Childhood obesity continues to be a growing health issue in the US and across the world. Children's risk of becoming obese may start from their earliest days on earth.
A recent study looked at how feeding practices might affect a child's risk of being obese at age 2.
The researchers found that breastfed babies were much less likely to be obese as toddlers than formula fed babies.
Babies were also more likely to be obese at 2 years old if their parents introduced them to solid foods before 4 months old or if their parents put them to bed with a bottle.
The study, led by Benjamin G. Gibbs, PhD, a professor in the Department of Sociology at Brigham Young University in Utah, aimed to understand how baby feeding practices might influence a child's obesity risk.
The researchers used data from a long-term study with 8,030 children who were tracked from 9 months old to kindergarten. The study group represents a typical group of American children born in 2001.
The researchers gathered data on whether the children were breastfed or formula fed, when they first began solid foods and whether they went to sleep with a bottle. This information was based on interviews with the mothers when the babies were 9 months old.
Then the researchers looked at the children's obesity rates at age 2. Obesity at age 2 was determined as being in the 98th percentile for weight, which is 25 pounds or heavier for boys and 24 pounds or heavier for girls.
The researchers gathered demographic information about the families, including their socioeconomic status based on the family's household income, the parents' education levels and the parents' occupations.
The researchers also gathered data on the mothers' weight and age when they gave birth. Finally, they asked whether the mothers smoked, whether they had depression and whether they used daycare.
The researchers found that babies who were mostly fed formula for their first 6 months were two and a half times more likely to be obese when they were 2 years old compared to the babies who were exclusively breastfed until 6 months old.
Of the 1,225 babies (15 percent of the total) in the study who were predominantly breastfed until 6 months old, only 5.6 percent were obese at 2 years old.
Of the 2,495 babies who were predominantly formula fed until 6 months old (31 percent of the total group), 11.7 percent were obese at 2 years old.
Of the 4,310 babies who were breastfed and formula fed until 6 months old (54 percent of the total), 9.6 percent were obese at 2 years old.
Babies were also more likely to be obese at age 2 if their parents introduced them to solid foods before 4 months old and/or if the child went to sleep with a bottle.
Only 8.7 percent of the breastfed babies who went to bed with a bottle or received solid foods before 4 months old were obese at 2 years old.
However, among formula-fed babies, 39.9 percent of those put to bed with a bottle and 29.2 percent of those fed solids before 4 months old were obese at age 2.
Among those who were breastfed and formula fed until 6 months, 33.1 percent of the children put to bed with a bottle and 19.4 percent of the babies fed solids before 4 months old were obese at age 2.
The body mass index (BMI) of the child's mother was not strongly linked to whether the child was obese at age 2 or not. However, 30.7 percent of formula fed babies whose mothers smoked were obese at age 2, compared to 5.1 percent of breastfed babies whose mothers smoked.
Past research has already shown that babies from a lower socioeconomic status have a higher risk of becoming obese. The researchers in this study determined that a large part of that link relates to the family's baby feeding practices.
"The encouragement and support of breastfeeding and other healthy feeding practices are especially important for low socioeconomic children who are at increased risk of early childhood obesity," the researchers wrote.
The study was published April 2 in the journal Pediatric Obesity. No external funding was noted in the study. The authors declared no conflicts of interest.