PHILADELPHIA (CBS) – Chubby babies may be on the decline, and doctors say that is a hopeful sign in the fight against obesity.

A study of  children two and younger who were enrolled in a government assistance program found that the rate of kids at risk for obesity fell from almost 15 percent in 2010 to 12 percent in 2014.

Half of all U.S. infants up to 12 months old are enrolled in the program, according to MedicalExpress.

Dr. David Ludwig, director of obesity prevention at Boston Children’s Hospital, called the results encouraging but said, “It’s too soon to tell whether these new data represent a statistical fluke or evidence of real progress with the pediatric obesity epidemic. ”

Researchers say breastfeeding among participating women increased in 2009 and that can protect against obesity.

The report is in Tuesday’s edition of Pediatrics.