Another reason to avoid unnecessary use of antibiotics, especially in children: They may contribute to weight gain, according to a study in the International Journal of Obesity. Researchers from Johns Hopkins University analyzed health records of nearly 164,000 children ages 3 to 18 and found that those who had taken antibiotics at least seven times by age 15 gained, on average, an extra three pounds. That’s not much, but the researchers suggested that the cumulative effect may continue into adulthood.
The connection to weight gain is biologically plausible, since antibiotics kill harmful bacteria but also other species that are vital to gastrointestinal health and that may affect nutrient and calorie absorption as well as appetite. Antibiotics are essential, even life-saving, treatments for bacterial infections, but too often they’re inappropriately prescribed for colds and other viral infections that cannot possibly be helped by the drugs.