KEY POINTS:
They're everywhere. Plastic friends with fast-flow tops and people attached to them.
For some, the water bottle has become practically a fifth limb - dragged to the mall, the movies, the business meeting, the bedroom. But can you get addicted? And how much water are you supposed to drink?
Believe it or not, "aquaholics" are no longer a rarity in international medical circles. As sales of the now-fashionable water bottle continue to soar, so do the numbers reporting they just can't live without their bottle.
The benefits of drinking plenty of water have also become more confused - there's been a shift away from the "eight glasses a day" mantra.
Some scientists, including Robert Walker, head of Otago University's medical and surgical sciences department, now believe people should drink only when they're thirsty, that more water doesn't flush toxins, and that the eight-glass-a-day rule has no scientific basis.
There was even concern people were overdosing on good old H2O, Walker said. Hyponatremia is a deadly condition where the brain swells as the body fails to cope with too much water.
And psychogenic polydipsia is a listed psychological condition describing an overwhelming compulsion to drink.
Dozens of internet accounts describe people - mainly women - who cannot leave their water bottles alone.
Lawyer Wendy Locke noticed first-hand the water-sipping habit take hold in one of her friends. "You know how people get a cigarette out and tap it on the packet when they're thinking? She would do the same ritual with her water bottle.
"Take it out of her bag, take the lid off, hold it, take a couple of slow slips - and then make her point. It was really irritating."
She added that some judges hated water bottles in their courtrooms.
But local addiction specialist Peter Adams, of Auckland University, doubted whether sipping on a water bottle could get so bad as an "addiction" in the way people became addicted to alcohol or drugs.
"If it was the case that a person's water bottle had become more important than their partner, or their child, then you could say an addictive pattern had emerged."
Auckland gym owner and fitness author Paul Richards said constantly sucking on a water bottle could be a kind of status symbol.
"Drinkers are making a statement that they are proactive about health. But contrast the 'annoyance' of someone sucking on water to someone with smoker's breath."
He believed water drinking helped prevent senility. Dr Andrew Kilding, director of the sports performance centre at AUT, said like water bottles, bottled sports drinks with added ingredients to replace what was lost in our sweat had become hugely popular with athletes.
He said there was no recommended daily dosage of water that could be applied universally. Top athletes had "individual hydration plans" to work out how much water they should drink. After a bout of exercise, the athlete should not have lost more than 2 per cent of their body mass, he said.
Despite debate over the claims of sports drinks, Kilding believed they were beneficial, at least for serious athletes. "You sweat out salt. If you just replace that with water, then you are essentially diluting your blood."
Biljana Knaap, naturopath and director of natural health care company Nature's Science, said many clients were dehydrated, which occurred when the body's "inner hydration system" was not doing its job. The water might be going straight in, and straight out. "People who drink 2 litres of water a day may still have a problem if the water is not being absorbed into the tissues."
Like many countries, New Zealand has seen phenomenal growth in bottled water sales. In 1993, we guzzled 159,027 litres, but by 1999 it was 4.5 million litres. Present annual supermarket sales are worth $43,708,000.
The industry has experienced double-digit growth for the past five years, said Aaron Fundars of The Good Water Company, which uses environmentally friendly plastic bottles.
A "proud" water addict who drinks five to seven 650ml bottles a day, Fundars and his business partners saw huge potential in the market with eco-friendly packaging. The company, which donates 10c from every bottle sold to the Sir Peter Blake Trust, aims to be the first to recycle its bottles in New Zealand. They will be turned into underground cable covers.
Hydration test
Drink three glasses of water in a row when your bladder is empty, but not within five minutes of going to the toilet. Time how long it is before you need to pee. If your body is using the water correctly, it should be 45-50 minutes. If it's 15-20 minutes, then you are dehydrated, and probably in need of sodium replacement.
Consult a health professional for further advice.
Hitting the bottle hard
Thirsty Shelley Miles loves to hit the bottle. Water bottle, that is. The Auckland sales manager takes comfort in her liquid of choice while working hard at the gym, sculling back at least a litre and a half of the good stuff - and that's before lunch.
Her plastic friend then accompanies her throughout the day - there's always a bottle in her car - and Shelley is prone to shunning other drinks in favour of her favourite, H2O.
"I drink three litres a day, easy. I just sip it all day," the water addict confessed to the Herald on Sunday. "I find it much more refreshing than anything else. I've given up coffee."
Luckily, her "addiction" isn't unfashionable.
"It's trendy to be seen with your water bottle. I think we are following an American trend. It's very noticeable over there."
Angela Powney is another who can't be without her bottle. A hairdresser, she's on her feet all day, water bottle never far from her side. "I'm lost without it," she told the Herald on Sunday, only half-joking.
"It's the only drink that quenches my thirst."
Health benefits from regular supping were noticeable, she reckoned. "Sometimes, if I feel a headache coming on, I'll look over at the bottle and notice I have only had a quarter. I think generally I don't get as many headaches because of the amount of water I drink."
She used to buy her bottled water, though had recently switched to refilling from the tap, or from a jug of boiled water, to significantly reduce the cost of her habit.
"I realised I was spending quite a bit on it."
Angela's bottle even accompanies her into the bedroom, where it sits within arm's reach on the bedside table for a night-time fix. The water habit is a good one, she said. The only downside is the frequent bathroom trips.
"Sometimes I do have a bit too much..."
