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t_Articles
Until you suffer from a sweating brow and a parched
mouth, you probably don't give much thought to fluids. Yet maintaining
enough fluid is vital to most body functions. You've probably heard the
saying that water is essential for life. Well, it's true. We can survive
for about six weeks without food but less than a week without taking
fluids.
Water, water everywhere
Just as it is the most abundant material on earth,
water is the most abundant substance in the human body, making up one
half to two thirds of body weight. Roughly three quarters of the brain
and muscles are made up of water. Even bone is 20 percent water.
The percentage of water in the body varies from
person to person depending on such factors as body composition, age and
gender. For example, men have more water in their bodies than women
because they have a higher content of lean muscle. Muscle holds more
water than fat tissue.
Every part of the body, from the individual cell to
the entire circulation system, depends upon water to function. Water is
needed for:
- Transporting nutrients and oxygen to all parts of the body via the
blood and lymphatic system.
- Helping maintain body temperature. (Heat is released when you
sweat, which helps to cool you down).
- Lubricating the joints to keep them moving freely.
- Removing body waste materials.
- Serving as a medium for thousands of reactions that need to take
place in the body daily to sustain life.
- Maintaining blood volume.
Don't wait until you get thirsty
While it varies depending on weight, climate and
activity levels, experts recommend that most people drink 21/2 to 3
litres of fluid daily. That's at least eight glasses a day - or a drink
for every hour of the working day.
The normal trigger for drinking is thirst, which is
regulated by the amount of sodium (salt) in the blood. As the sodium
content increases, receptors in the brain's hypothalamus trigger the
thirst sensation. At the same time, "thirsty" blood draws water from the
salivary glands. This is why we get a dry mouth when we haven't had
enough to drink.
But by the time we get thirsty, we are already
slightly dehydrated.
"People tend to assume that thirst is a good
indicator of fluid requirements. However, thirst is actually a sign that
the body is already slightly dehydrated. Fluid levels need to be
replenished before thirst even sets in," said Julie Howden, nutritionist
and executive director of the Asian Food Information Centre (AFIC).
When the body has become slightly dehydrated, the
kidneys respond by conserving water and reabsorbing it back into the
blood instead of removing it from the body as urine. This results in
less urine being formed.
Most people don't drink enough
Most people do not drink enough fluids. A recent
survey in Singapore by Temasek Polytechnic and AFIC showed that women
drank just 5 to 6 glasses of fluid daily while men averaged 6 to 8
glasses a day. The only groups that were found to drink the recommended
minimum of 8 cups a day were older women aged 55 to 64 years and younger
men aged 25 to 34 years.
Another survey in Hong Kong showed that half of those
surveyed failed to drink 8 cups or more of fluid daily with nearly one
in three drinking less than 5 cups of fluid a day.
People who are exercising need even more fluid. This
is especially important if your workouts are in a hot and humid climate
since sweating increases the loss of fluids . The American College of
Sports Medicine recommends drinking before, during and after exercise.
Two glasses (half a litre) of fluid two hours before exercising and
regular drinks during exercise can help replace fluid lost through
sweating. Rehydration after exercise is important to restore the
appropriate fluid level in your body.
WHAT'S YOUR FLUID?
With such a wide variety of fluids to choose from,
there's really no excuse for not drinking enough.
Water:Always a great choice. Drink it hot or cold
or try adding sliced lemon or lime cordial for a refreshing change.
Milk:A great way to get calcium, protein and
fluid at the same time. Try a low-fat milkshake blended with your
favourite fruit or flavouring.
Juice:High in vitamins, this is a good way to
start the day.
Tea:Whether green, black or oolong, tea has been
shown to contain antioxidants, making it a healthy choice. Try it with a
slice of lemon or lime. Or vary the type of tea you drink.
Coffee:Shown to improve concentration levels,
this may be the right choice for that afternoon fluid break. Try cooled
coffee poured over ice cubes for a treat on a hot day.
Soup:An old favourite and a good supplier of
fluids. Start a meal with soup.
Soft drink:Lots of varieties to choose from.
Drink well-chilled for instant refreshment.
Fruits & vegetables:Many fruits and vegetables
contain up to 80 percent water. Aim for five servings a day
Desserts:That favourite ice-kachang is also a
good source of fluid. Great for hot days.
FREQUENT EXCUSES FOR NOT DRINKING ENOUGH FLUID
Here are the most frequent excuses in Singapore for
not getting enough to drink
- "I wasn't thirsty." Nearly half of all respondents gave this
answer. Remember, by the time you are thirsty, you are already
slightly dehydrated.
- "I forgot." One in five people said they forgot to drink enough
(probably because they weren't thirsty).
- "It's too troublesome." So are the end-results of not getting
enough to drink such as headache, tiredness, poor skin and bad breath.
Make it easy to get enough fluids by keeping a variety of drinks you
enjoy close at hand.
- "I don't want to visit the bathroom very often." Not drinking
enough is one of the most common causes of constipation. Remember that
the next time you're tempted not to drink for this reason.
Based on a survey by Temasek Polytechnic and AFIC,
1999.
TOP TIPS ON GETTING MORE FLUID
- Leave a jug or container of fluid on your desk and fill your glass
frequently until it's all gone.
- Take a drink every time you stop for a break.
- Drink a variety of fluids so that you don't get bored with the
same beverage all the time.
- Carry a drink with you everywhere you go, even in the car.
- Remember to drink more if you're exercising or if it's very hot.
SIGNS OF DEHYDRATION
The effects of dehydration range from thirst and
weakness to impaired kidney function. In extreme cases, dehydration can
even lead to coma and death.
Signs of dehydration:
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Mild
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Thirst
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Headache
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Fatigue
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Flushed skin
- Dry mouth and throat
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Moderate
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Severe
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Muscle spasms
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Swollen tongue
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Poor blood circulation
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Increased weakness
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Failing kidney function
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