SSS 2010-08-24（在线收听）

Americans, and American physicians, are concerned about ballooning waistlines and the accompanying health problems. Now, researchers have presented the first randomized trial of what they hail as a side-effect-free, prescription-free, and simply free appetite control agent. That is, of course, water. Brenda Davy, lead researcher from Virginia Tech, presented the findings at the National Meeting of the American Chemical Society.

Previous studies showed that middle-aged and older Americans who drank two cups of water before a meal ate about 75 to 90 fewer calories over the course of the meal. For this study, the scientists took 48 adults between 55 and 75. All ate a low-calorie diet for 12 weeks. Half of the group drank 16 ounces of water before meals. The other half didn't.

After the 12 weeks were over, the water drinkers lost on average 15.5 pounds, while the ones who weren't prescribed water lost about 11 pounds. Davy says that this phenomena could occur because water is filling and has, of course, zero calories. It could also be displacing other, sweeter drinks that the dieters might consume. It's not a cure-all, but it's certainly a cheap and simple addition to any weight-loss plan.

Thanks for the minute. For Scientific American's 60-Second Science. I'm Cynthia Graber.