If the typical person ages one year at a time, the typical president, Dr. Michael Roizen told CNN in 2009, ages two years for every year they are in office.
And it shows.

Bill Clinton was 46 when he took office. He was 54 when he left.

George W. Bush was 54 when he took office. He was 62 when he left.

President Obama was 47 when he took office. He’s 52 now.