Obesity rates will reach 42 percent: US study

The prediction by a team of researchers at Harvard University contradicts other experts who say the nation's obesity rate has peaked at 34 percent of the U.S. population.

The finding is from the same group, led by Nicholas Christakis, that reported in 2007 that if someone's friend becomes obese, that person's chances of becoming obese increase by more than half.

They now think this same phenomenon is driving the obesity epidemic, which will climb slowly but steadily for the next 40 years.

Alison Hill, a graduate student at Harvard and the Harvard-Massachusetts Institute of Technology Division of Health Sciences and Technology, said the study is based on the idea that obesity can spread like an infectious disease and people can catch it from their friends.