Can it really be that successful weight loss follows something as simple as filling up on water before you eat a meal?
by Craig Weatherby
Apparently so. And if overweight people can consistently down water before every meal, then it’s curtains for Jenny Craig, Weight Watchers, and the folks who peddle dubious weight loss pills.
Last week, scientists reported results of a three-month clinical trial, whose results confirm that drinking two eight-ounce glasses of water before meals leads to substantial weight loss.
The news that water can help us lose weight seems shocking in the age of pricey commercial diet plans and “miraculous” weight-loss pills.
The weight-loss findings were presented at the 240th National Meeting of the American Chemical Society (ACS), and the study was funded by The Institute for Public Health and Water Research.
“We are presenting results of the first randomized controlled intervention trial demonstrating that increased water consumption is an effective weight loss strategy,” said senior author Brenda Davy, Ph.D., of Virginia Tech.
Dr. Davy went on to say, “…we found that over the course of 12 weeks, dieters who drank water before meals, three times per day, lost about 5 pounds more than dieters who did not increase their water intake.”
She pointed out that folklore and everyday experience long have suggested that water can help promote weight loss. But there has been surprisingly little scientific information on the topic.
Dr. Davy cited an earlier study by her group, which showed that middle aged and older people who drank two cups of water right before eating a meal consumed 75 to 90 fewer calories during it (Van Walleghen EL et al. 2007).
And while her Virginia Tech team detected no calorie intake cuts among young people in that 2007 study, their later study showed that obese people over 60 consumed 13 percent fewer calories during breakfast when they drank water before the morning meal (Davy BM et al. 2008).
But until now, we’ve lacked “gold-standard” evidence from a randomized, controlled clinical trial that compares weight loss among dieters who drink water before meals with those who do not.
Watery study proves H2O’s weight loss potential
The study involved 48 adults aged 55-75 years, divided into two groups: One group drank 2 cups of water prior to their meals and the other did not.
All of the subjects ate a low-calorie diet during the study. Over the course of 12 weeks, water drinkers lost about 15.5 pounds, while the non-water drinkers lost about 11 pounds.
As the authors concluded, “Thus, when combined with a hypocaloric [low calorie] diet, consuming 500 ml [16 ounces of] water prior to each main meal leads to greater weight loss than a hypocaloric diet alone in middle-aged and older adults” (Dennis EA et al. 2010).
Davy said drinking ample water before a meal may work simply because people feel fuller and eat less calorie-containing food during the meal.
Increased water consumption may also help people lose weight if they drink it in place of sweetened calorie-containing beverages, said Davy.
Diet soda pop and other beverages with artificial sweeteners may also help people reduce their calorie intake and lose weight, Davy said.
(The evidence on artificial sweeteners for weight loss is mixed. And we’d advise you to learn about the safety concerns surrounding aspartame, and the scientifically and ethically dubious way in which the FDA approved the sweetener… as described in a segment of CBS-TV’s “60 Minutes” news show.)
However, it makes no sense to try to cut calories by quaffing beverages sweetened with sugars before a meal… a typical eight-ounce glass of regular soda or fruit juice contains about an ounce (28 grams) of sugar and 112 calories.
How much water is enough for health?
Nobody knows exactly how much water people should drink daily, and a recent study found that the conventional medical advice—to drink eight eight-ounce glasses per day—has no basis in research.
The U.S. Institute of Medicine says that most healthy people can simply let thirst be their guide. It does not specify exact requirements for water, but set general recommendations for women at about 9 cups of fluids—from all beverages including water—each day, and men at about 13 cups of fluids.
At that there is little risk that drinking two cups before each meal will produce any problems.
While it is possible to drink too much water and thereby suffer a serious condition known as water intoxication, this is a rare occurrence.
American Chemical Society (ACS). Clinical trial confirms effectiveness of simple appetite control method. August 23, 2010. Accessed at http://portal.acs.org/portal/acs/corg/content?_nfpb=true&_pageLabel=PP_ARTICLEMAIN&node_id=222&content_id=CNBP_025391
Davy BM, Dennis EA, Dengo AL, Wilson KL, Davy KP. Water consumption reduces energy intake at a breakfast meal in obese older adults. J Am Diet Assoc. 2008 Jul;108(7):1236-9.
Dennis EA, Dengo AL, Comber DL, Flack KD, Savla J, Davy KP, Davy BM. Water consumption increases weight loss during a hypocaloric diet intervention in middle-aged and older adults. Obesity (Silver Spring). 2010 Feb;18(2):300-7. Epub 2009 Aug 6.
Dennis EA, Flack KD, Davy BM. Beverage consumption and adult weight management: A review. Eat Behav. 2009 Dec;10(4):237-46. Epub 2009 Jul 16. Review.
Van Walleghen EL, Orr JS, Gentile CL, Davy BM. Pre-meal water consumption reduces meal energy intake in older but not younger subjects. Obesity (Silver Spring). 2007 Jan;15(1):93-9.