When I was a kid, I was able to sit in a classroom for an hour (or even two) without requiring rehydration. Adults were able to go for a walk without toting a drink bottle. And the only reason to carry water in a car was to refill the radiator.

When did we become a nation requiring constant hydration? Somehow we have all come to believe that drinking is a core part of being healthy. Kidney Health Australia helped propagate the message that we should all be drinking eight glasses of water a day. And even the official dietary guidelines chimed in to tell us that we should be getting two litres a day. Unsurprisingly, they got plenty of support from water authorities and bottled water manufacturers.

Unfortunately, there is no scientific basis whatsoever for such a recommendation. Hydration has nothing to do with kidney health. It turns out that high blood pressure and diabetes are the primary risks to our kidney health. And we’re suffering more than ever before. End stage kidney disease (the bit just before you die) in men increased by 31% between 2000 and 2007 (19% for women). And because you can get by on just 10% kidney function without showing symptoms, most kidney disease goes undiagnosed.

But try as they might, Kidney Health Australia is having difficulty stuffing the drink-water-for-kidney-health genie back in the bottle. We love a health message that encourages us to do something we were going to do anyway. We’re even keener to do it if we can convince ourselves it’s cool.

OK, we weren’t going to drink two litres of water a day (well, not after the first day). But we pretty quickly convinced ourselves that any drink counted. As long as we were getting the required fluid volume. Big Sugar was more than happy to help us with our self delusion.

Coca-Cola, for example, has a special site dedicated to letting us know that “water* plays many important roles in the body”. The asterisk is there to remind us that “it’s not just plain drinking water that contributes to hydration” (just in case you temporarily forgotten they’ve got some sugary stuff to sell to you).

But there probably aren’t too many people who believe a bottle of Coke is really health food (with the possible exception of Kerry Armstrong). It’s much more of a problem when this kind of intentional deception sneaks into the marketing of children’s drinks.

School canteens don’t sell soft drinks these days. And schools certainly don’t encourage children to sip Pepsi throughout the day. They don’t do it because the various state health authorities have declared soft drinks to be too full of sugar to be safely consumed by children. Instead they sell water. No, not plain old boring tap water. It’s water, but “fun”.

Wacky Water and Play Sports Water have the school canteen market sown up. They’re made by P&N Beverages and the lead line from the Wacky Water website sums up its approach to the market. It says “Do you find drinking the amount of water that nutritionists recommend difficult?”

Both drinks are targeted firmly at worried parents. They fret that little Hermione and Reginald are dehydrated (and their kidneys are on the verge of packing it in) but they know they have Buckley’s of getting them to drink enough water. Solution: Wacky, Sporty, Water.

These waters are sweetened with pure fructose. Somehow this counts as neither added sugar (which it is) nor artificial sweetener (which it also is) by the time it gets onto the Fun, Wacky, Sporty labels of these bottles of (what looks like) pure fresh water (they leave the colouring out for some reason). Education departments are happy that everyone is being healthy. Parents feel less guilty. And kids can’t believe they’re actually being encouraged to drink this stuff.

A 500ml bottle of Sports Water delivers 21g of pure fructose to the thirsty child. To get that much fructose from sugar, you’d have to chow down on 10 teaspoons of the white gold.

Inconveniently, it seems that all that natural fructose causes chronic kidney disease. So these waters are not exactly having the desired effect.

A study released last month confirmed that fructose directly causes high blood pressure. It does this by raising uric acid levels in the blood. High uric acid levels are known to cause kidney disease, as is the high blood pressure itself. Eighty per cent of patients with failed kidneys have high blood pressure.

Every day in Australia seven new patients are added to the list of people requiring dialysis or transplantation of failed kidneys and the rate is accelerating. One in 10  deaths are now as a result of kidney disease. What are these numbers going to look like by the time the kids we’re stuffing with fructose wear out their kidneys?

Our children will drink water when they are thirsty. So make sure there is water available in the playground. But every day that fructose-laden drinks are sold as water adds more kids to the back of the queue for a new kidney.

Fructose is deadly. There is no justification for selling it to our children as health food. It’s time our governments (and those they pay to care) pulled the pin on this disgusting display of corporate greed at the expense of children’s health.