Christina Aguilera knew visiting war-torn Rwanda would be eye-opening. But it wasn't until she spent time in Kigali, Rwanda, on a hunger relief mission this June – visiting refugee camps and seeing the severe poverty firsthand – that she discovered just how profoundly moving the experience would be.
"This trip came at a time when I really needed to step away and connect with bigger issues in the world, [and] this trip really touched me in a way I never felt before," says Aguilera, who is the global spokesperson for Yum! Brands World Hunger Relief effort and an Ambassador Against Hunger for the UN World Food Programme.
"I came home and really wondered about why some people are born to some situations and others are born in a different place," The Voice star tells PEOPLE. "I had to come to terms with a little guilt even for coming home and not doing more. The people of Rwanda touched me in a way I cannot express or put into words. They are in a place that needs our help and I am so proud of the work that we are doing there."
The time she spent with hundreds of Rwandan children during the trip was especially poignant for the Aguilera, who couldn't help but think of her 5-year-old, Max.
"After the birth of my son, I started looking into causes that touched me as a mother and I was so moved by the work the World Food Programme and Yum! did," says Aguilera, who has also visited Haiti and Guatemala on behalf of the group.
"As a mom, to know that there are kids that go to bed hungry is just not acceptable. Food is a human right in my mind and knowing that I can help means so much. In Rwanda, we visited a school. The kids walk approximately two miles to get there, not only to learn but for many this is their only meal of the day."
Even with her busy career and hectic life as a working mom, Aguilera has no plans to stop trying to help fight world hunger. Almost as soon as she returned home from Rwanda, she was sure of one thing: "I know I will go back."