Rates of women who are obese may be linked to the fact that women are performing less household chores and sitting more, a new study in the journal PLoS ONE reveals.

According the study, done by the University of South Carolina nearly two-thirds of adult women in the United States are overweight or obese. Researchers believe a factor in this may be that they are spending less time on housework.

The investigators reviewed activity logs kept by stay-at-home mothers from the American Heritage Time Use Study for the years of 1965 until now. Childcare was not included in this data.

They found that on average, the amount of time women spent on domestic household chores fell from 25.7 hours a week in 1965 to 13.3 hours a week in 2010.

In a comment to CBSNews.com, Edward Archer, a research fellow with the Arnold School of Public Health at the University of South Carolina in Columbia, and lead author of the study said:

“We wanted to look at where are women spending their time because most of them were working a single shift in the household taking care of children (in 1965). Later on they were working a double shift … spending eight hours doing whatever job they are doing and then no matter what, they came home and took care of the kids so they had a second job.”

For women who worked outside the home, they performed 6.7 hours per week of housework in 2010 and burned 132 less calories doing it than compared to the year 1965.

Assuming these women did the same amount of housework each day, women used to burn approximately 857 calories each day in the 1960’s and now they are burning 200 calories less a day.

This finding doesn’t imply that women should be spending the majority of their time scrubbing the floors and vacuuming, however it does emphasize the importance of regular physical activity as a significant factor in overall health and weight control.

Additionally, the authors found that the rates of watching TV and movies, and use of computers rose. Time spent in front of a screen increased from 8.3 hours a week in 1965 to 16.5 hours a week in 2010.

For working women there was an average of 7.5 hours a week of screen time in 2010, while women who did not work spent 9.6 hours in front of a screen per week.

The authors commented, “The reallocation of time from active pursuits (i.e., housework) to sedentary pastimes (e.g., watching TV) has important health consequences.”

The authors pointed out that because women have become less active, their children are now being born with more fat cells, producing more weight issues.

Archer concluded to CBSNews.com:

“We’ve engineered physical activity out of our daily lives. By no means does this mean that women should do more housework, but they’re now doing less (calorie-spending activities) than they were doing in the past, and we need to integrate more activity back in their life.”

In 2008, a study carried out by a team at University College London showed that vigorous housework once a week is associated with lower levels of depression, anxiety, and stress.

Written by Kelly Fitzgerald