Kids who receive antibiotics throughout the course of their childhoods gain weight significantly faster than those who do not, according to new Johns Hopkins Bloomberg School of Public Health research.
The findings, published online October 21 in the International Journal of Obesity, suggest that antibiotics may have a compounding effect throughout childhood on body mass index (BMI), a measure often used to determine whether someone is at a healthy weight.
“Your BMI may be forever altered by the antibiotics you take as a child,” says study leader Dr. Brian S. Schwartz, a professor in the department of environmental health sciences at the Bloomberg School. “Our data suggest that every time we give an antibiotic to kids they gain weight faster over time.”
For the study, Dr. Schwartz and his colleagues analyzed Geisinger Health System’s electronic health records on 163,820 children between three and 18 years old from January 2001 to February 2012. They examined body weight and height (which are used to determine BMI) and antibiotic use in the previous year as well as any earlier years for which Geisinger had records for the children.
At age 15, children who had taken antibiotics seven or more times during childhood weighed about three pounds more than those who received no antibiotics, they found. Approximately 21 percent of the kids in the study, or almost 30,000 children, had received seven or more prescriptions during childhood. Schwartz says that the weight gain among those frequently prescribed antibiotics is likely an underestimate since the children did not stay with Geisinger throughout childhood so their lifetime antibiotic histories, including antibiotic use outside the health system, would not have been recorded and because the effect of certain antibiotic types was even stronger than the overall average.