They're living on a basic daily diet of a small amount of porridge, plain rice and plain beans for five days as part of Tearfund's Mean Bean Challenge.
Carol Monaghan, a Christian and the SNP's MP for Glasgow North West, is taking part to highlight the plight of those who have to live on the same subsistence-level diet.
Monaghan said: "I'm doing the Mean Bean challenge because I think it's a really tangible way of connecting with the harsh realities of poverty that millions of people face every day.
"I am sure living on so little food will be difficult for me but many people have no choice."
More than 800 people in the UK have signed up for the challenge, which has so far raised more than £40,000 for Tearfund's work in countries including Ethiopia, Kenya, Malawi and South Sudan.
Other people to being urged to get involved.
Monaghan added: "It's a privilege to do this challenge to support Tearfund and the work they do in more than 50 countries around the world - including in East Africa where we are seeing famine taking hold."
Tearfund projects including feeding centres, support for expectant mothers and farmer training are set to benefit from funds raised by the Mean Bean Challenge.
International director Myles Harrison, who is also taking part, said: "Here in the UK we are often detached from the everyday difficulties families and whole communities are facing.
"Doing the Mean Bean challenge not only brings this home (I am wondering how I am going to get through the week and still be able to work!) but also helps to raise money for our projects which are providing lifesaving assistance in over 50 countries.
"Why not join in too and get your family and friends to sponsor you?"