When he was 19, Liederman went to France, he met the Troisgros brothers, which led to his interest in finding a career preparing food. In 1990 David co-wrote a diet book called ''David's Delicious Weight-Loss Program'' with
freelance writer Joan Schwartz. In the mid-1990s Liederman opened a theme restaurant, Television City, in
Rockefeller Center. Liederman sold David's Cookies in 1996. After being acquired by the New Jersey–based Fairfield Gourmet Foods Corp., David's Cookies evolved into a full line dessert supplier. Despite being more known for his cookie products, Liederman's passion was the restaurant world. He would open various restaurants, including grills, throughout the state of New York. ==Personal life and death==