Antibiotic use in infants could later lead to an overweight childhood, according to new studies.

Researchers from New York University studied more than 10,000 children and found that those given antibiotics before six months of age on average weighed more for their height than children who weren't given antibiotics.

The findings, published Tuesday in the International Journal of Obesity do not claim that antibiotics in early life causes young children to be overweight, but suggest there is a direct connection.

"We typically consider obesity an epidemic grounded in unhealthy diet and exercise, yet increasingly studies suggest it's more complicated, said Dr. Trasande, leader of study.

"Microbes in our intestines may play critical roles in how we absorb calories, and exposure to antibiotics, especially early in life, may kill off healthy bacteria that influence how we absorb nutrients into our bodies and would otherwise keep us lean."

According to the researchers farmers have known of the relation between antibiotics and weight gain for years, often using antibiotics to produce heavier cows.

"While we need more research to confirm our findings, this carefully conducted study suggests that antibiotics influence weight gain in humans, and especially children too," said Jan Blustein, professor of health policy at the NYU Wagner School of Public Service.