Researchers at the University of South Carolina compared activity logs kept by stay at home women from 1965 until the present day.
Women used to spend an average of 25.7 hours a week cooking and cleaning and that dropped to about 13 hours in 2010.
The average American woman who works at home is now 22 pounds heavier.
Some critics question the motives of Coca-Cola, who funded the study, and they point out that men are also heavier.
