India, June 16 -- Mitzi Perdue, the 84-year-old heiress to not one, but two American business empires, Sheraton Hotels and Perdue Farms, is a rarity in a world where wealthy individuals often show off their fortune through private jets and couture wardrobes. She chooses hand-me-downs over designer threads and prefers fixing her old shoes to buying new ones.

She could have spent her life floating above it all in first class. Instead, she stands firmly on the ground, living in a middle-class apartment and taking the subway like any regular commuter. In a recent interview with Fortune.com, Perdue opened up about why she chooses a modest, service-oriented life despite her billionaire legacy.

Perdue's story begins in 1941, as the fifth child...