| Although it contains no nutrients, water is
a vital component of our diets. It's essential for the growth
and maintenance of our bodies, as it's involved in a number
of biological processes. But most of us don't get nearly
enough.
Why do we need water?
Water comprises 50 to 70 per cent of an adult's total
body weight, and without regular top-ups, our body's survival
time is limited to a matter of hours or days.
Water is lost from the body through urine and sweat, and
must be replaced through our diets. Many people, though,
don't consume enough and as a result may become dehydrated,
causing symptoms such as headaches, tiredness and loss of
concentration. Chronic dehydration can contribute to a number
of health problems, such as constipation and kidney stones.
How much do we need?
The body gets its water from three sources:
From drinks, either plain water or as part of other beverages.
From solid foods, especially fruits and vegetables.
As a by-product of chemical reactions within the body.
The British Dietetic Association advises that the average
adult should consume 2.5 litres of water per day. Of this,
1.8 litres - the equivalent of six to seven glasses of water
per day - must be obtained directly from beverages. This
should be increased during periods of hot weather or during
and after periods of physical activity.
Water is the major ingredient of all drinks: carbonated
and still drinks are 65 per cent water, diluted squashes
are 86 per cent water (after dilution) and fruit juices
are 90 per cent water. But drinking plain water is still
the most effective way of replacing lost fluids.
Bottled waters
What about bottled waters? There are two types of bottled
water: spring water and mineral water. Spring water is collected
directly from the spring where it arises from the ground
and must be bottled at the source. UK sources of spring
water must meet certain hygiene standards, but may be treated
in order that they meet limits set on pollution.
Mineral water emerges from under the ground, then flows
over rocks before it's collected, resulting in a higher
content of various minerals. Unlike spring water, it can't
be treated except to remove grit and dirt. Different brands
of spring and mineral waters will have differing amounts
of minerals depending on their source.
In 1999 Government regulations came into force covering
the labelling requirements of bottled waters, to help consumers
make informed choices about the products they buy. As a
result, the levels of all minerals in natural mineral water
must be listed on the label.
But is it necessary to buy bottled water? The drinking
water available from our taps is perfectly adequate to replenish
our fluid loss, and undergoes many processes to bring it
up to the standards set out in the Water Supply Regulations.
In 1999, according to Which? Online, 98.8 per cent of tap
water sampled passed drinking water inspectorate tests.
There are certainly no proven health benefits of bottled
water over tap water - it basically comes down to personal
taste and cost. |
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