A new study appearing in the latest issue of Obesity Reviews claims to show that modern conveniences such as computers, but also washing machines and microwaves, are turning people into lazy piles of mush at an alarming rate.

Using time-use studies from the 1960's to present day, researchers from the University of North Carolina at Chapel Hill's Gillings School of Global Public Health have determined that home appliances meant to make our lives easier have done just that — to the detriment of our health.

Dr. Shu Wen Ng and Dr. Barry Popkin used units of energy expenditure called METs — or metabolic equivalent of task — to measure the amount of physical activity residents of different countries engaged in over time. For example, in the 1960's, Americans expended 235 MET hours per week. But by 2009, that number fell to just 160 MET hours per week.

A similar decline was seen in the UK, where MET hours dropped from 216 in 1965 to 173 in 2005. Brazil, India, and China all experienced decreases in MET, with China's decline being the sharpest: 399 MET hours in 1991 compared with 213 less than two decades later.

And the numbers are expected to drop even further, with MET hours per week reaching a paltry 126 in the US within the next twenty years.

The researchers place just as much blame on the types of tasks people perform in their everyday jobs as they do on technology. They attribute the move from agriculture to manufacturing in developing countries to the steep decline in physical activity there.

Ng and Popkin conclude with an ominous look ahead: "Given the potential impact on weight gain and other cardiometabolic health risks, the differential declines in MET of activity and increases in sedentary time across the globe represent a major threat to global health."

[image via WALL-E]