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Archer investigates PAR protocol to evaluate average physical activity among U.S. adults

March 18, 2014

Edward Archer, PhD, postdoctoral fellow in the Office of Energetics, recently validated a novel method for estimating physical activity, sedentary behavior, and the food energy requirements of U.S. citizens. The results were surprising and suggest that as a nation, we spend most of our lives (more than 16 hours per day) sleeping and sitting, and that obese men and women spend less than sixty seconds per day in vigorous activity. These estimates were derived from the U.S. National Health and Nutrition Examination Survey, which is comprised of data collected between January 1, 2005, and December 31, 2006.

The study established that in 2005-2006 the food energy requirements for the U.S. population were 2,940 calories per day (Cal/d) for men and 2,275 Cal/d for women, and ranged from a high of 3,230 Cal/d in obese men to a low of 2,026 Cal/d in normal weight women (defined by BMI below 25). There were significant inverse relationships between physical activity and both obesity and age. Men were more active than women overall, while obese men and women were less active than normal weight individuals, and younger individuals were more active than older individuals.

Dr. Archer and his fellow researchers concluded that this new protocol, known as the Physical Activity Ratio or PAR protocol, is an accurate method for deriving nationally representative estimates of both physical activity and food energy requirements. The descriptive data calculated in the study provide novel baseline values for future investigations into associations of physical activity, diet, and health. The findings gained national attention when reported last month in the Los Angeles Times (,0,2080046.story#axzz2u4NIYooe) and when Dr. Archer was interviewed on Huffington Post Live ( )

“Physical inactivity is the greatest public health problem we have in the 21st century,” says Dr. Archer. “With the results from this study taken into account, and the overwhelmingly sedentary nature of the current U.S. population, the message to ‘move more, sit less’ is sound, empirically supported advice that is easily understood by health care professionals and the public.”

To read “Validation of a Novel Protocol for Calculating Estimated Energy Requirements and Average Daily Physical Activity Ratio for the U.S. Population: 2005-2006,” published recently in the journal Mayo Clinic Proceedings, click here.