August 23, 2010
By Susan Brady

Research is backing up what common sense and most diet plans [1] already know, that drinking water—more of it at strategic times—can help in weight loss. It’s no surprise that that free-flowing liquid available everywhere in the world is not only good for you but can also curb your appetite.

Brenda Davy, associate professor in the Department of Human Nutrition, Foods and Exercise at Virginia Tech, and a team of researchers conducted a study comprised of middle-aged and older Americans who were either overweight or considered obese. Participants were put on a low-fat, low-calorie diet and divided into two groups, the only difference being one group had to drink 2 glasses of plain water prior to every meal.

After a period of 12 weeks, the water-drinking group had lost an average of 15.5 pounds per person, while the control group averaged 11 pounds. Those two cups of water before each meal translated into a 30 percent weight loss differential.

Researchers had concerns that the water-drinking group would fill up on water and eat less during the meal, but compensate later by having a snack, however this was not the case. Water not only provides a feeling of fullness, it can also reduce hunger pangs. The catch?— because you know there always is one—the 2 glass water trick only works in older adults, and is not useful to dieters in the 18-35 age range. Apparently in older adults  it takes more time for the stomach to empty, providing a longer period of satiety than in younger adults.

The study was presented today at the annual meeting of the American Chemical Society.