There's a saying that presidents age twice as fast while in office. With Thursday marking President Barack Obama's 55th birthday, take a look back over the past 60 years of U.S. presidents and judge for yourself how much the office aged them.
Former President George H.W. Bush is seen here attending an NCAA Men's Basketball Tournament game in Houston, Texas, with former first lady Barbara Bush on March 19, 2015. Bush was 90 when this photo was taken.