14-pound baby, Joel Jr. is currently holding the title for the biggest baby born in the US this 2013, and doctors revealed that his rather bigger than average size is attributed to his mom's type 1 diabetes, ABC News reported Friday.

According to several reports, Sara Brandon gave birth to 14-pound Joel Brandon Jr. or "J.J." last May through cesarean section, after her doctor prompted her that ultrasound results showed her baby was close to weighing 11 pounds.

However, after giving birth to J.J. doctors and nurses were shocked when they found out that he was already weighing 14 pounds flat. "When they stuck him on the scale he was 14 pounds even," Brandon told ABC News. "The doctor said it was the biggest baby he had ever delivered."

KSL.com reported that J.J. beat Germany's Jasleen, who was born at 13.74 pounds last July. However, the claim to the biggest baby born title for the this year still belongs to George King from England, who was born at a whopping 15 pounds and 7 ounces.

Meanwhile, another American baby was also reported to be a contender. Addyson Gale Cesana of Pennsylvania was born sporting 13 pounds and 12 ounces.

Based on Brandon's experience, her 14-pound baby's delivery was quite different from her birth-giving experience with her twin girls, who roughly weighed 8 pounds put together.

Chief of Obstetrics and Gynecology at Brigham and Women's Hospital in Boston Dr. Robert Barbieri said that the J.J.'s size was mainly due to his mother's type 1 diabetes.

"An interesting effect of insulin, if it's not taken in a sufficient amount, the glucose remains high, and the baby's glucose starts to rise," Barbieri said. "It's like giving the baby fertilizer and it grows very large."

Barbieri revealed that about one out of 1,000 babies are born weighing 11-pounds while in 100,000 could weigh 14 pounds or more. Because of the 14-pound baby's rather large frame and lung problems, J.J. had to spend his first 10 days in the neonatal intensive care unit, but ever since he was released from the hospital, he is said to thrive happily.

"He's very calm, content and giggly. He sits with his sisters all day. He only cries if he's hungry or tired," Brandon said on her son's condition. "He's an awesome little guy, or big guy."