SITNFlash

Hello SITN community! Below you will find this month’s SITNewsflash based on an interesting recent research article in Science that studies how the calories you burn and your overall body weight may reflect the small unnoticed movements you make during the course of your day. You can refer to the links below the article for more information on this topic (And feel free to post questions on this topic or others to our Question and Answer page, where you will get a personal answer to that questions that’s been itching you from one of our volunteers!) Also, please check out the announcements at the bottom of the page for information on interesting new lectures taking place at the Harvard Medical School this spring.

Obesity and its health complications are an epidemic in the United States and other Western nations. As a consequence, billions of dollars are spent annually on diet plans and gym memberships that promise to control our waistlines, and drug companies race to market with new weight loss medications for overweight individuals. But a recent study in the journal Science suggests that in addition to our diet and exercise routines, fidgeting can help us control our figure.

Non-exercise activity thermogenesis, or NEAT, is the subject of this study. NEAT is the term used to describe the energy we expend on commonplace daily activities such as standing, walking, talking, sitting, and yes, fidgeting. Weight gain results when energy intake (from food) exceeds energy expenditure (calories spent from exercise). NEAT, our small changes in body position during regular daily activity, can contribute a sizable amount to the calories that are expended during the day and thus, to the maintenance of our body weight in general. Researchers at the Mayo Clinic examined whether there were differences in NEAT among lean and overweight people. To measure this, they developed a technologically advanced suit of underwear, loaded with sensors, for research subjects to wear throughout the day for ten days. When worn, the system gathered information on posture, body position, and physical activity every half-second, giving researchers a glimpse into the behavior patterns of the volunteers and number of calories expended through NEAT-related activities.

The results were surprising. The overweight volunteers were in sedentary positions for more than two and a half hours a day longer than the leaner, but still self-described “couch-potato” volunteers. This difference corresponds to a large reduction in the measured number of calories expended in the form of NEAT throughout the day by the overweight volunteers. If the overweight volunteers were “as fidgety” as their lean counterparts, they might burn as many as 350 calories more a day from NEAT activities which could add up to 40 pounds of body weight in a year! Furthermore, when lean volunteers gained weight and overweight volunteers lost weight, their respective amounts of NEAT did not change. Researchers concluded from this that “fidgeting”-related energy expenditure may be biologically determined and not a result of one's current body weight. So, natural restlessness may cause the thin to stay thin.

Drawing on this preliminary study, the researchers stipulate that overweight people may be more likely to choose to sit if the opportunity presents itself, thus causing them to remain overweight. They argue that perhaps small environmental changes at work and at home to increase daily small movements may lead to less obesity overall.

Primary Source:

Levine, J.A., et al. “Interindividual Variation in Posture Allocation: Possible role in Human Obesity.” Science v 307(Jan 28). 2005; 584-586

Other great related material:

http://www.nytimes.com/2005/01/27/health/28weightcnd.html?ex=1108011600&en=c8cc21ec1b8098bc&ei=5070

http://www.npr.org/templates/story/story.php?storyId=4468682

http://theedge.bostonherald.com/healthNews/view.bg?articleid=65625