Ben Affleck, Sophia Bush, Josh Groban and Debi Mazar are among the celebrities who are taking part in the 2013 Live Below the Line challenge by living on $1.50 a day to raise awareness of global poverty.
The challenge, issued by The Global Poverty Project, will have all participants spending just a dollar and a half a day on food and drink for one week, from April 29 to May 3.
The meager daily amount is the current equivalent of the accepted global figure used to define extreme poverty.
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Live Below the Line aims to help people better understand how it is for the 1.4 billion others who live in extreme poverty. The campaign also hopes to help fundraising to support partner organizations.
Affleck tweeted about taking the challenge, encouraging others to participate too.
Three years ago, Affleck founded the Eastern Congo Initiative, a US-based advocacy and grant-making organization that give the people of Eastern Congo economic and social development opportunities.
Hugh Jackman, who sits on the Global Poverty Project's board, started the Live Below the Line challenge in 2011 and appeared in public service announcements. More than 20,000 are expected to participate in this year's campaign.
More than $3 million was raised for the project last year.