Frequent Antibiotic Use Linked With Weight Gain in Children


The International Journal of Obesity has published a study that found children who use antibiotics regularly are gaining weight more rapidly than children who have never taken them.

Further, the research shows that the antibiotics may affect a person’s body weight into adulthood. The New York Times’ Tara Parker-Pope writes the researchers examined medical records of 163,820 youngsters aged three to 18 to count antibiotic prescriptions, body weight, and height from 2001 through 2012.

The results showed that one in five children had been prescribed antibiotics seven times or more. When the subjects reached the age of 15, they weighed an average of 3 pounds more than children who had not taken antibiotics.

Studies performed earlier did show a relationship between the use of antibiotics and childhood weight gain, but the data had to rely on the subject’s mother for her memory of her child’s antibiotic use. This study is unique because it uses documentation of antibiotic use on the children’s medical records.

“Not only did antibiotics contribute to weight gain at all ages, but the contribution of antibiotics to weight gain gets stronger as you get older,” said Dr. Brian S. Schwartz, chief author of the study and professor in the environmental health sciences department at the Johns Hopkins Bloomberg School of Public Health.

Scientists are and have been aware of the fact that antibiotics cause weight gain in livestock and that food producers use the drugs for that reason.

The reason for the weight gain could be because the antibiotics kill healthy bacteria in a child’s body. The loss of the bacteria may lead to chronic changes in the microbiome, the multitude of organisms found in the gut, and may shift the way food is broken down in children’s bodies.

A Danish study published in July found that a mother’s use of antibiotics can also affect her child’s weight gain.

The research team does not want parents to think they should never give their children antibiotics – many illnesses are life-threatening and require antibiotic treatment – but the idea is to create a new strategy to curb the drug’s use when possible.

“We’ve got to totally dissuade parents from advocating for antibiotics,’’ said Dr. Schwartz. “As parents we want to feel like we’re doing something active for our kids, but I think we’re doing our kids damage. If your doctor says you don’t need them, don’t take them. ”

Schwartz said antibiotics could influence weight gain at any age, yet they are one of the most commonly prescribed drugs. They have been go-to drugs for so long that there is a growing problem of resistance to them, according to Guatam Naik of The Wall Street Journal.

Since being overweight or obese is now the top health concern for children, with 1 in 3 US kids falling into the category, the new study has had a significant impact on the medical community. Marie Ellis, writing for Medical News Today, reports that physicians are becoming more cautious about prescribing antibiotics.

“Systematic antibiotics should be avoided except when strongly indicated,” says Dr. Schwartz. “From everything we are learning, it is more important than ever for physicians to be the gatekeepers and keep their young patients from getting drugs that not only won’t help them but may hurt them in the long run.”

Macrolides, a class of antibiotics for bacterial infections, were associated with the most weight gain, says Samantha Costa, reporting for US News and World Report. These medications also go by the names erythromycin, azithromycin, and clarithromycin.