- Drinking two cups of water before all three meals helped dieters lose weight and keep it off.
- The findings only worked in people who were middle-aged and older, but water might help younger dieters, too.
- Americans get far too many calories in the form of sugar-filled beverages.
It's a popular dieting secret: Drink more water, and you'll shed more pounds. Finally, science is adding weight to the practice.
After about three months, a new study found, obese dieters who drank two cups of water before each meal lost 5 pounds more than a group of dieters who didn't increase their water intake. A year later, the water-drinkers had also kept more of the weight off.
The study included only middle-aged and older adults, but other studies suggest that drinking water might help dieters of all ages, said Brenda Davy, a nutrition researcher at Virginia Tech in Blacksburg. After years of folklore, she added, this may be the first hard evidence that pounding water is viable weight-loss strategy.
"It's this popular idea that, oh yeah, drink more water -- that's what you have to do when you want to lose weight," said Davy, who presented her new findings today at a meeting of the American Chemical Society in Boston. "It seems to be logical, but it had never really been investigated."
Davy and colleagues reported one of their first findings in 2008 in the Journal of the American Dietetic Association. That study found that older adults who drank two cups of water half an hour before breakfast ate about 75 fewer calories -- or 13 percent less -- than a comparable group who hadn't drunk water before the meal. People in both groups were overweight or obese, and all were allowed to eat as much of the food as they wanted.
To see if that behavior would lead to actual weight loss, the researchers started by putting more than 40 overweight and obese adults on a diet. The dieters, all between the ages of 55 and 75, were instructed to eat healthy meals that totaled no more than 1,200 to 1,500 calories a day.
Half of the dieters were randomly assigned to drink a 16-ounce bottle of water before all three meals. The others received water but were not given any instructions about when or how to drink it.