Health advice seems to shift on a monthly basis. One month vitamin megadoses are the key to longevity; the next month they're suspected of triggering some fatal conditions. The New York Times Book of Health includes dozens of articles, dating back to 1993, that show these changes in scientific thought. Don't expect to find basic how-to information here; for the most part, only the aspects of health and fitness that were newsworthy--the moderate- vs. strenuous-exercise debate, for example--are included. Still, this makes for a nice compilation of what science knows about us in the late 1990s and how the newspaper of record has covered it.