"I met a little boy on that trip who was seven years old, but he looked like he was four because when you're that badly malnourished ... your growth is stunted, your mental capacity is stunted," she recalled.
"So this little boy, you could tell, was in such physical pain because he literally just hadn't gotten the proper food and nutrition he needed.
"So that was the moment I was like, 'Wow.' World hunger goes from being a statistic to being this little boy, which was just heartbreaking."
The granddaughter of former U.S. president George H. W. Bush and niece of ex-president George W. Bush met the boy and countless others during her travels with the UN World Food Programme.
Bush Lauren visited countries within Africa, Asia and Latin America and also served as a WFP student spokesperson. She took particular interest in the school feeding program, and wanted to find a way to help others engage in the issue of world hunger.
She co-founded the FEED Foundation, which seeks to end hunger among the world's children. As of last year, the foundation has provided 60 million school meals to kids worldwide.
The Princeton graduate is also the brainchild behind the charitable FEED bag, a burlap tote reminiscent of those used by WFP to distribute food to people in need.
American designer Tory Burch is putting her own signature stamp on the latest incarnation of the bag. Proceeds from the limited-edition $50 tote available through Holt Renfrew will benefit both FEED and Burch's eponymous foundation, which supports economic opportunities for women, including providing microloans to female-owned small businesses.
Before marrying David Lauren — son of fashion icon Ralph — last year, Bush Lauren had carved out her own niche as a designer with a fashion line aiming to fuse style with a social conscience.
"During my travels, I've also been so moved by artisans and seeing the handiwork and traditional craft that people are still practicising around the world," she said. "So in creating my own little fashion line, Lauren Pierce, I wanted to source fabric and support these women artisans in particular.
"I found this amazing group of women in the (Democratic Republic of) Congo ... and they're hand-dyeing these beautiful fabrics in all these amazing colours and patterns; and so I was able to use that fabric to create more wearable, Western-type pieces."
Bush Lauren also sought to connect fashion consumers with the artisans who had a hand in crafting the raw materials. To that end, on the back of each dress features the name of the woman who hand-dyed that particular piece of fabric. She also incorporates use of such eco-friendly fabrics as organic wools and hemp silks into her line.
Long before becoming the public face of her current projects, Bush Lauren said her sense of social consciousness took shape early on.
"I was lucky to kind of grow up in a family where we always talked about public service and we'd always go volunteer," she said. "We were made to be aware at a young age that we were very lucky and there are many needs out there that need to be addressed."
Bush Lauren said she loves the creative challenge of addressing problems and helping people in need, but seeks to do so in a way that is "engaging and fun and hopeful."
"I think through design you can really do that," she said.
"I feel very lucky to have sort of stumbled into this new way of doing business, which is a social business around giving back, and creating products that hopefully people not only love to wear but be very proud of what they're doing also."