Couch Potatoes Shed Light on Obesity

Obese "couch potatoes" sit more and walk less than lean "couch potatoes" living in the same environment, according to a new study in the 28 January 2005 issue of the journal Science. These findings may be important for understanding the biology of obesity and how best to treat this worsening epidemic.

The researchers continuously measured the posture and body position of 20 sedentary volunteers for 10 days. All volunteers were self-proclaimed "couch potatoes," but 10 were lean and 10 were mildly obese. On average, the lean individuals stood and moved around about two hours longer each day than the obese individuals.

After lean participants gained weight and obese participants lost weight, the researchers monitored both groups for another ten days. Each group retained its original movement pattern, which suggests that time spent walking versus sitting could be biologically determined.

If obese individuals moved through each day like their lean counterparts, they could expend an additional 350 kilocalories per day.

The research clearly demonstrates that small but sustained changes in the activities of daily living can profoundly affect energy balance, according to the author of a related "Perspective."

— Daniel B. Kane

28 January 2005