How to Live to Be 100

George Stephanopoulos interviewed Jeffrey Cluger, senior editor of Time magazine, about what it takes to live to be to 100 years old.

During the interview on "Good Morning America," Stephanopoulos said that the Census reported in 2007, more than 83,400 people in the U.S. were older than 100. By 2050, that number is expected to reach 800,000.

One of the main reasons they've reached that age is their ability to bounce back from disease.