World Hunger Relief was founded by Pizza Hut owners Yum! to provide meals for impoverished children around the world.
Aguilera explained that she became a World Hunger Relief global spokesperson in order to set a good example for her son Max.
"As a mother, the idea that even one child would go to bed hungry is unacceptable and that's why I'm so passionate about fighting global hunger," she said. "I'm excited about my new PSA for World Hunger Relief this fall and hope it will raise more awareness about the issue and move millions of people from hunger to hope."
Aguilera also posed for a World Hunger Relief print campaign, which will be displayed in Yum! brand restaurants including Pizza Hut and Taco Bell from this fall.
The Voice judge recently promised that her next studio album will be "heartfelt".
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Watch Christina Aguilera discuss her World Hunger Relief PSA and The Voice below: