jennifer aniston
Jennifer Aniston's Rachel in 'Friends' smoking.Screenshot/YouTube

The world celebrates "No Tobacco Day" on Sunday, 31 May, and is intended to encourage a 24-hour period of abstinence from tobacco consumption.

In 2015, WHO aims to stop the illicit trade of tobacco products on World No Tobacco Day and is partnering with other global organisations to highlight the health risks associated with tobacco use, and effective ways to reduce its consumption.

If you are looking for some inspiration, here is the list of some celebrities who quit smoking:

Barack Obama: If you thought your excuse for smoking was stress, then think again. Because the president of the United States of America quit smoking a couple of years ahead of his first presidential term in 2007. He has publicly admitted that it is an ongoing struggle and passed an anti-smoking bill in an attempt to protect future generations from picking up the habit.

Jennifer Aniston: The "Friends" star had reportedly struggled for many years before completely quitting smoking in 2007. The former chain-smoker attributes Yoga as the main incentive for her change. 

Catherine Zeta-Jones: "The Mask of Zorro" actress, who was photographed smoking during the last stages of her pregnancy in 2003, vowed to quit smoking in 2005 for the sake of her children. However, she has had difficulty stopping, suffering many relapses.

Michael Douglas: Catherine's husband Michael Douglas has also struggled with smoking habits. In 2011, a cancerous tumour was found in Douglas' throat, which made the "Behind the Candelabra" actor try and quit the unhealthy habit.

Gwyneth Paltrow: Now a health enthusiast, Gwyneth Paltrow used to be an addict in the teenage years, smoking an average of two packs a day. Even though her father died of cancer in 2002, the former wife of Coldplay's Chris Martin could not kick the habit. However, when she found out that she is pregnant with her first child in 2004, she resolved to stop smoking.