(MODEL RELEASED IMAGE). Tama Matsuda, 100 years old, watches as her daughter-in-law Keiko, 75, proudly shows images of Tama at different ages. (Supporting image from the project Hungry Planet: What the World Eats). The Matsuda family is one of the thirty families featured in the book Hungry Planet: What the World Eats (p. 186). Hara hachi bu "eat only until 80 percent full," say older Okinawans. The island has been the focus in recent years of researchers trying to discover why a disproportionately large number of Okinawans are living to age 100 or more.