According to one estimate, 1.4 billion people around the world have to get by on just $1.50 a day. To bring awareness to that fact, Ben Affleck will spend only that much on food and drink for "at least one day" next week. Sophia Bush, Josh Groban, Debi Mazar, and Hunter Biden are also taking part in the challenge as part of a campaign from nonprofit Live Below the Line to raise funds for the Global Poverty Project, TV Guide reports. They'll be tweeting their experience. The campaign runs Monday through Friday, and participants are encouraged to "live below the line" for all five days.