One-third of 9-month-olds already obese or overweight

The path toward obesity starts at a young age — even before babies transition to a solid diet, according to a new study.

Almost one-third of 9-month-olds are obese or overweight, as are 34 percent of 2-year-olds, according to the research, which looked at a nationally representative sample of children born in 2001. The study is one of the first to measure weight in the same group of very young children over time, said lead researcher Brian Moss, a sociologist at Wayne State University in Detroit. The results showed that starting out heavy puts kids on a trajectory to stay that way.