How much should you drink?

The amount of water you need depends on many factors: your health status (including whether you're pregnant or breastfeeding), your age and weight, how active you are, and the climate you live in. According to the Ministry of Health, New Zealand males need about 2.6 litres (about 10 cups) of fluid a day and females about 2.1 litres (about 8 cups). Foods, like fruit and vegetables, also contribute to your fluid intake.

A healthy diet can rely on water alone - you can be perfectly healthy without drinking tea, coffee or alcohol. But life would be boring without a refreshing juice, or a quenching cup of tea. And milk is an important source of calcium in our diet.

The problem is that some drinks are loaded with kilojoules, so they can contribute to weight gain.

A latte on your way to work, a can of Coke with lunch, a juice before the gym, and a beer after work. It doesn't sound like much, but adds up to about 2500 kilojoules. That's more than a quarter of some people's energy intake for the entire day.

Does it matter?

Unfortunately, yes. Thirty percent of Kiwi kids aged between 5 and 14 years are considered overweight or obese, and so are more than half of Kiwi adults.

Kilojoules are the bottom line when it comes to maintaining weight, and liquid kilojoules go down easily.

Studies have shown that if you shift from a kilojoule-free drink like water, to a kilojoule-laden drink such as soft drink, you don't adjust your diet to take account of the extra kilojoules. And older children and adults are less likely to cut back on something else, compared with younger children.

Frequent consumption of sugary drinks may also contribute to poor dental health. All sugar, whether it is natural or added, has the same effect on teeth. You also have to be wary of sugar-free drinks and sports water because these contain food acids, which erode tooth enamel.

Food acids are also naturally present in oranges and other fruit. Drinks with a pH of less than 5.2 may contribute to tooth decay (for the pH levels of different drinks, see our table of drinks compared).

The damage can be minimised if you keep sugary and acidic drinks for mealtimes. This is when saliva production is high. Saliva helps protect the teeth by washing the sugar and acid away. Avoid sipper bottles for drinking sweet and acidic drinks. These can be disastrous as sipping something sugary over a long period of time is the surest way to damage teeth.

Don't forget the importance of regularly brushing your teeth, either.

What are we drinking?

Kiwis spend $1.2 billion a year on non-alcoholic beverages. That's 640 million litres of soft drinks, fruit juice, bottled water, sports and energy drinks, and flavoured milk. Males drink more coffee, soft drinks and cordial. Females prefer diet soft drinks, water and herbal teas.

The 2002 National Children's Nutrition Survey reported that nearly 40 percent of Kiwi kids drink milk every day. But over 25 percent of their sugar intake comes from drinks such as powdered drinks, soft drinks, and fruit drinks. This is about six percent of their total energy intake.