Dr. Reubin Andres, 89, a gerontologist who advanced the study of diabetes but gained his widest attention for arguing that weight gain in older people increases longevity, died Sept. 23 at his home in Baltimore. The cause was heart disease, said his daughter, Julie Schwait. He had been clinical director of the National Institute on Aging since 1977 when he began examining weight gain a few years later. He had been asked to address a 1980 conference on obesity and mortality in New York and, not knowing much about the topic, he began investigating the literature.

"For some reason the idea has grabbed us that the best weight throughout the life span is that of a 20-year-old," Andres said in a 1985 interview with The New York Times. "But there's just overwhelming evidence now that as you go through life, it's in your best interests to lay down some fat."

He was not advocating obesity. "It is not my contention that the fatter the better," he said. "It is my contention that the desirable range rises with age." Andres' statements provoked an outcry from those in the medical profession who saw fat as the enemy of good health.

Stanford R. Ovshinsky, 89, an iconoclastic, largely self-taught and commercially successful scientist who invented the nickel-metal hybrid battery and contributed to the development of solar energy panels, flat-panel displays and rewritable compact discs, died Wednesday at his home in Bloomfield Hills, Mich.

Placing Ovshinsky in "the league of genius inventors," The Economist magazine once titled an article about him "The Edison of Our Age?" If not quite that, he was certainly among the 20th century's most inventive breed of scientists who, like Edison, parlayed their ideas into practical commercial applications.