The 'Argo' director-and-actor will live on a meagre $1.50 to raise awareness of extreme poverty worldwide and insists he and other stars who have leant their support to the initiative are doing so for the right reasons.
Writing in a blog post on The Huffington Post, Ben said: "Some accuse it [the challenge] of making the issue of extreme poverty into little more than celebrity Twister. It is also true that celebrities often promote (knowing or unknowingly) lifestyles that price out all but the richest Americans."
The 40-year-old Oscar-winner recognises the huge divide of wealth in America but insists he shouldn't feel guilty about having a luxurious lifestyle as long as he offers his help to people who are less fortunate than him.
He explained: "The issue is not that we should feel guilty about owning cars and Xboxes; taking vacations or buying fancy shoes. It's that we should understand that we have a responsibility as a country to be good global citizens.
"We have a responsibility to come to the aid of our neighbors, some of who are literally starving to death."
Affleck - who has three children, Violet, seven, Seraphina, four, and 13-month-old Samuel, wife Jennifer Garner - began his $1.50 challenge on Wednesday and believes that everyone should do what they can to try and end poverty.
He wrote: "Today I engage in the minor act of eating rice and beans to do my tiny part. I encourage others to do whatever they can, however minimal."
Ben, who has visited the Congo eight times, is an avid campaigner in the fight against poverty and has started his own charity called the Eastern Congo Initiative to improve nutrition and prevent disease in the African nation.