Drinking Water May Speed Weight Loss

Metabolic Rate Increases Slightly With Water Consumption

Jan. 5, 2004 -- Whether your weight-loss strategy espouses carbs with
no fat or protein with few carbs, there is one thing your plan most
certainly recommends -- water. From the veggie-based Ornish diet to
steak-loving Atkins (and virtually all diets in between) "drink lots
of water" is part of the mantra.

Now comes scientific evidence that H2O really does help you lose
weight. Researchers in Germany report that water consumption
increases the rate at which people burn calories. The impact is
modest and the findings are preliminary, but the researchers say
their study could have important implications for weight-control
programs.


Eight Glasses a Day

Despite the fact that most diets call for drinking at least eight, 8-
ounce glasses of water a day, few studies have been done to determine
if the practice actually speeds weight loss. In an effort to answer
this question, Michael Boschmann, MD, and colleagues from Berlin's
Franz-Volhard Clinical Research Center tracked energy expenditures
among seven men and seven women who were healthy and not overweight.

After drinking approximately 17 ounces of water, the subjects'
metabolic rates -- or the rate at which calories are burned --
increased by 30% for both men and women. The increases occurred
within 10 minutes of water consumption and reached a maximum after
about 30 to 40 minutes.

The study also showed that the increase in metabolic rate differed in
men and women. In men, burning more fat fueled the increase in
metabolism, whereas in women, an increased breakdown of carbohydrates
caused the increase in metabolism seen.

The researchers estimate that over the course of a year, a person who
increases his water consumption by 1.5 liters a day would burn an
extra 17,400 calories, for a weight loss of approximately five
pounds. They note that up to 40% of the increase in calorie burning
is caused by the body's attempt to heat the ingested water. The
findings are reported in the December issue of The Journal of
Clinical Endocrinology and Metabolism.


"Very, Very Small Effect"

The researchers write that up to 70% of the increase in
metabolism, "cannot be attributed to the heating of the ingested
water," but exercise physiologist Daniel Moser, PhD, tells WebMD that
it is unclear from this small study if this is the case.

"Larger studies are clearly needed to confirm this extremely modest
weight-loss effect," he tells WebMD.

Nutritionist and American Dietetic Association spokeswoman Leslie
Bonci, MPH-RD, says even if the findings are confirmed the clinical
implications are slight.

"Obviously people are looking for ways to increase metabolism, but
this is an very, very, small effect," she tells WebMD. "We are
talking about just a few calories a day."

Bonci says the standard weight-loss plan dictates encouraging people
to drink more water stems from the belief that the liquid fills the
gut to make people feel fuller.

"Some plans say that drinking water flushes fat out of your system,
which is absolutely ridiculous," she says.

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SOURCES: Boschmann, M. Journal of Clinical Endocrinology and
Metabolism, December 2003; vol. 88: pp. 6015-6019. Leslie Bonci, MPH,
RD,spokeswoman, American Dietetic Association; director, sports
nutrition, University of Pittsburgh Medical Center. Daniel Moser,
PhD, exercise physiologist, Elite Health and Wellness, Philadelphia.