Some Foods Raise Dehydration Risk

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Some Foods Raise Dehydration Risk

Sun May 5,12:02 PM ET

By IRA DREYFUSS, Associated Press Writer

WASHINGTON (AP) - What athletes take in may dry them out. Fast foods like

hamburgers and carbonated drinks such as sodas can wind up causing

dehydration, experts say.

Sugary, caffeine-packed soft drinks, in particular, can cause trouble, said

Dr. I. Wadler of New York University School of Medicine. A cola's sugar

and the carbonation can make a person feel full without providing enough

liquid.

" They are very sweet, so you get bloated. They are gaseous, so they distend

you, so you get more bloated, " Wadler said. And caffeine, which tends to

increase the flow of urine, " is a double whammy, " he said. " You lose on all

counts. "

Former tennis star Jimmy Connors used to be one of Wadler's patients.

" He used to get these horrific total body cramps. It was sort of a mystery, "

Wadler said. " I found out he was drinking cola drinks in great quantity, and

he was getting bloated. Because he was bloated, he was not drinking adequate

fluids. "

The risk is not limited to sodas, researchers say. Protein breakdown

requires water, and the protein in a couple of fast-food hamburgers can

leave people dehydrated, a researcher said.

" We didn't have to make them sweat, " said nutrition researcher

who conducted a dehydration study. " The hamburger meat was enough. "

Although her study did not measure athletic performance, the amount of

dehydration would have been enough to make an endurance athlete perform

worse, said , who works at California State University, Fresno, and

is also spokeswoman for the American Dietetic Association. The study was

conducted to help NASA (news - web sites) develop rehydration fluids for

astronauts. It was published as a NASA internal memo in 1992.

Time spent sleeping also leaves people dehydrated, so the researchers had

their test subjects eat the burgers before bedtime, to make the dehydration

worse.

A separate study presented last month in New Orleans at Experimental Biology

2002, a conference of seven research-oriented professional societies, found

that athletes who took in more protein wound up more dehydrated.

" The concern is that increasing protein increases the work the kidney has to

do, and can impact the amount of fluid needed to get rid of waste, " said

researcher of the University of Connecticut.

That study, led by graduate student F. , examined five members

of the university's track team. The athletes were placed on supervised

high-, medium- and low-protein diets. All the athletes spent a month on each

level. " We fed them everything they ate for the four weeks of the diet, "

said , senior author of the preliminary report.

The low-protein diet worked out to about 68 grams a day for a 150-pound

person; the medium-protein, to 123 grams, and the high-protein, to 246

grams.

The low protein diet was mostly grains, augmented by some beef and dairy

foods, said. The medium-protein diet was equivalent to the level

that athletes - and most Americans - normally have, she said. The high-level

diet was mostly meat, supplemented by nutrition bars to add to the protein

intake, she said.

The high level would be very unusual, but not uncommon for body builders,

football players and others trying to add much muscle, said.

The athletes also got bottled water, and filled out forms each day on how

much water they drank from any source, said. " I was very conscious

of keeping them hydrated, " she said.

As the amount of protein rose, the athletes' kidneys had to work harder as

the body tried to get rid of the excess protein, the study found. There was

a higher proportion of protein breakdown chemicals such as nitrogen in the

urine of athletes on the high-protein diet.

The researchers took those findings as signs that athletes on high-protein

diets were losing more water. And because there was no evidence the athletes

were drinking more, the scientists concluded the men were dehydrated.

It doesn't take much dehydration to reduce an athlete's ability to perform.

Being about 1 percent below optimal fluid level can reduce exercise

performance. said her study did not test performance because

testing could have impaired the athletes' readiness to compete.

But the athletes did not notice being more thirsty, and did not report

drinking more, as their protein levels rose, the study found.

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