A new study supports US guidelines that recommend parents wait to give their babies solid foods until they are at least 4-6 months old.

"Adhering to those guidelines could reduce the risk of obesity in childhood," said Dr. Susanna Huh, one of the study’s lead authors from Children’s Hospital Boston

For babies who were breastfed for at least four months, the age at which they first received solid food (anywhere from four to six months of age) did not matter — either way, these kids had a one in 14 chance of being obese at age three.

However, for formula-fed babies, as well as those who stopped breastfeeding before four months of age, the chance of being obese at 3 yrs. was an astounding 25 percent if they started eating solids before the four month mark.

The probability of obesity went down dramatically to one in twenty if parents waited to give solid foods until the baby was 4-5 months old. And it seemed to shoot back up if parents waited until the baby was more than six months old, although there were too few babies in this condition for the researchers to make a final conclusion about the more-than-six-months-old obesity risk.

Researchers say that breastfeeding lowers a child’s risk of obesity, and that they should wait to eat solid foods until they’re at least four months old. The reasoning behind this is effect in infants is similar to the principle of overeating in adults.

Transitioning to solid foods, especially for babies who are raised on formula, could mean a huge increase in the number of calories they’re consuming. Parents are sometimes too quick to do this before they’ve learned how much energy (read: "food") their baby really needs.

"That’s exactly how (adults) get overweight," said Dr. David McCormick, a pediatrician at The University of Texas Medical Branch at Galveston. "They eat a little bit more than they should every day."