Leo Kahn was born in Medford, Mass., on Dec. 31, 1916, to parents who had immigrated from Lithuania. He graduated from Harvard and Columbia Journalism School, worked as a reporter at a small Massachusetts newspaper, and served as a navigator for the Army Air Forces in World War II. He joined his father’s wholesale grocery company and started a new retail division, which became Purity Supreme. Mr. Kahn’s partner in starting Staples in 1986 was Thomas G. Stemberg, who had previously been his biggest competitor in the New England grocery business. Mr. Kahn went on to start two chains of health food stores, Fresh Fields and Nation’s Heartland, which combined sharp attention to the demands of fitness-conscious consumers with price-conscious marketing. Mr. Kahn’s wife of 11 years, the former Dorothy Davidson, died in 1975. He is survived by his second wife, the former Emily Gantt; his sons Joseph, the deputy foreign editor of The New York Times, and Daniel; his daughter, Elizabeth Mallon; his stepdaughters, Lisa and Xandria Birk; eight grandchildren; and three step grandchildren.