As President Barack Obama gets ready to move out of the White House, the toll the presidency has taken on his body is plain to see.
Even back in 2011, two years into his first term, Obama found himself answering questions about his rapidly changing appearance -- particularly his gray hair.
"Obviously, I've gotten a little grayer since I took this job, but otherwise I feel pretty good," he told NPR before his 50th birthday, according to The Seattle Times. "And Michelle, you know, she says that she still thinks I'm cute, and I guess that's all that matters, isn't it?"
Some experts say the stress that comes along with being president causes a person to age twice as quickly as people with ordinary lifestyles.
"The typical person who lives one year ages one year," Dr. Michael Roizen told CNN, according to CBS News. "The typical president ages two years for every year they are in office."
Clemson University psychologist Dr. James McCubbin expressed a similar opinion, saying stress is to blame for the drastic changes we observe in a president's face and hair.
"Chronic stress can produce lots of wear and tear on the body," he said. "That is what we see in the changes in the appearance in the beginning and end of the presidency."
Obama was born Aug. 4, 1961, making him one of the youngest presidents in American history. He is set to leave office on Jan. 20 at the age of 55.