NORFOLK, Va. — Chubby cheeks and dimpled arms may be dismissed as baby fat in a toddler, but a study of local children suggests pediatricians need to raise concern about weight for tots as young as 2.

That’s the age the new study tags as a “tipping point’’ when children who become overweight start putting on more pounds than others. Some begin outpacing peers earlier.

Doctors affiliated with Children’s Hospital of The King’s Daughters teamed with a medical resident from Eastern Virginia Medical School to review the records of overweight children in South Hampton Roads, Va. The cases were from pediatric practices that serve Chesapeake, Norfolk, Suffolk and Virginia Beach.

Medical resident Vu Nguyen looked at the most recent wave of records this summer. They included 111 children with an average age of 12. Each child had at least five pediatric visits during which height and weight were measured.

The children were classified as overweight if their body mass index — a measurement of a child’s weight to height — exceeded 85 percent of the population. The charted information showed that more than half the children became overweight at or before their second birthdays, and 90 percent became overweight before reaching their fifth birthdays.

The information mirrored data that Dr. John Harrington, a Children’s Hospital pediatrician, had gleaned from records of 91 children in 2007 at a pediatric practice at the Norfolk-based hospital. Harrington cautioned that the study of children’s health records, which has yet to go through a peer review, is retrospective and only includes children identified as overweight.

“It doesn’t mean every child who weighs more than average at 2 will go on to be overweight,’’ Harrington said. However, the study does suggest that children who fight the bulge begin outweighing their peers at an early age, rather than at ages 8, 9 or 10, said Harrington, who worked with Nguyen and CHKD pediatrician Lawrence Pasquinelli on the study.

“We were looking for the point when they break off from regular kids,’’ Harrington said. He said he believes interventions by doctors and other health professionals need to happen earlier.