Dorothy asks: Does water make us fat?
Wynnie says: One litre of water weighs one kilogram. If you drink water and then jump on the scales, you will weigh more than usual, but you won't actually have put on weight: there aren't any calories in water, so there are no 'excess' calories to cause weight gain. Any water you drink is used to rehydrate your body, and any excess is excreted via your kidneys.
Water is the elixir of life, yet research shows most people regularly don't drink enough. The 2007 Behavioural Risk Factors Survey by the Department of Health in Hong Kong shows that nearly a third of adults drink fewer than six cups of fluids a day.
This falls considerably short of health recommendations, which say people living in moderate climates should drink at least eight 250ml glasses of fluids to prevent dehydration, and more if it's especially hot and humid, if you're exercising or are sick.
Although healthy humans can live for up to 60 days without food, they can't live for longer than a few days without water.
Our bodies contain about 38 to 45 litres of water. Water is needed for various functions such as regulating our temperature; transporting nutrients and oxygen to our cells and taking waste products and toxins away; lubricating our mouth, eyes and nose; as components for our blood, saliva, digestive stomach acid and urine; lubricating and moistening joints; and protecting organs such as our lungs and heart.
We lose about 10 cups of water a day through sweating, urinating, breathing and bowel movements. A shortage of water in the body can cause dehydration. Mild dehydration can drain your energy levels; just a 2 per cent loss of body water can cause a 20 per cent reduction in your physical and mental performances at school.