Hospital-acquired c. diff infections—how to treat? Comparing ordinary dieting to intermittent fasting—which yields more weight loss? Metals from joint replacements may leak into brain; Why do seniors experience declines in their red blood cell counts? Weekend warriors rejoice—the equivalent amount of exercise crammed into two days equals mortality benefits of daily workouts; How to replenish low iron levels; Young anabolic steroid abusers risk premature heart problems.