A new study has made the fascinating discovery that the rise in desk jobs over the past 50 years has helped fuel the obesity epidemic. According to the study, less than 20% of jobs require even moderate physical activity, compared to over 40% of jobs in the 1960s.

The study, published in the journal PLoS ONE, found that the typical worker is burning 100 fewer calories on the job than he or she did 50 years ago:

In the early 1960’s almost half the jobs in private industry in the U.S. required at least moderate intensity physical activity whereas now less than 20% demand this level of energy expenditure. …

Over the last 50 years in the U.S. we estimate that daily occupation-related energy expenditure has decreased by more than 100 calories, and this reduction in energy expenditure accounts for a significant portion of the increase in mean U.S. body weights for women and men.

The report’s authors don’t recommend that you quit your office job and go back to tilling the land. Instead they say:

Given that it is unlikely that there will be a return to occupations that demand moderate levels of physical activity; our findings provide further strong evidence of the public health importance of promoting physically active lifestyles outside of the work day. Our estimation of a reduction of more than 100 calories per day in occupation-related energy expenditure over the last 50 years would have been adequately compensated for by meeting the 2008 federal physical activity recommendations of 150 minutes per week of moderate intensity activity or 75 minutes per week of vigorous intensity activity.

Trends over 5 Decades in U.S. Occupation-Related Physical Activity and Their Associations with Obesity [PLoS ONE via Bloomberg]

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