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.

‘If you were overweight at nine months old, it really kind of sets the stage for you to remain overweight at two years,’ Moss told LiveScience.

Tracking obesity

According to the Centers for Disease Control and Prevention (CDC), childhood obesity has tripled over the last three decades. In 2008, 19.6 percent of kids between the ages of 6 and 11 were obese.

But less is known about obesity rates in very young children. In fact, researchers hesitate to label children that young as ‘obese.’

Recent studies have raised the alarm about particularly large babies, however. One 2009 paper published in the journal Pediatrics found […]