When Duke Ellington started playing "Take the A Train" during the 1940s and 1950s, around 30 percent of North American adults were overweight.

Now the rate's near 70 percent.

If you want to avoid (or escape) that expanding demographic, listen to Duke's advice: Take public transportation. (The A train is the subway line that runs through Manhattan and Brooklyn, New York)

Seems guys who use what researchers are calling active transportation (walking, biking and taking public transit) are 7 pounds lighter than average; gals are 5.5 pounds lighter.

Proof comes from an analysis of 15 countries, including Australia, New Zealand, the European Union and North America.

The U.S. is the fattest and most car-dependent - only 5 percent of you walk, bike or take public transit to get around. Denmark is the thinnest (only 20 percent are obese), and nearly 58 percent of Danes walk, bike or take public transit to work.

Active transportation means you're changing your position frequently; standing, bending, walking, climbing stairs, sitting and then standing again; that sure describes a ride on the A train (to Dr. Oz's New York-Presbyterian Hospital). You're revving your metabolism, toning muscles and keeping your brain sharper.

So instead of singing Duke's hit "Don't Get Around Much Anymore," consider using active transportation the next time you head to the mall or to work. You'll reduce your carbon footprint and extend the benefits of your daily planned physical activity (start with 30 minutes a day and ramp up to 10,000 steps every day).

You didn't think you could get out of that, did you?

© 2014 Michael Roizen, M.D. and Mehmet Oz, M.D.
Distributed by King Features Syndicate, Inc.