I tried for a few months to drink more water a few years ago. The only change in my life was the amount of time I spent in the bathroom. I gave up, frustrated.

Experts always advise people to drink more water. It's also intuitively right. Water is essential for life because its unique molecular structure dissolves chemicals and enables them to move through the body and our cells.

Is it beneficial to your wellbeing to try to drink more?

First and foremost, why do we drink water?

The explanation is surprising

"What the body is really trying to do is control the salt material." Our bodies have a very narrow tolerance for the amount of salt in our blood. We die whether we eat too much or too little. The brain detects salt levels and tells the kidneys to pull (or stop pulling) water from the blood within seconds. We need to add water to our systems because we lose about 4% of our body weight every day, mainly through our lungs, skin, and urine.

We need to add water to our systems because we lose about 4% of our body weight every day, mainly through our lungs, skin, and urine.

Adults need between 2.1 and 2.6 litres of water every day, which are based on a detailed analysis of the evidence. “It is difficult to say ‘you must drink this amount' because all the factors that influence your hydration are so complex – body size, environment, activity,” says Clare Collins, a professor of nutrition and dietetics at the University of Newcastle. “However, for healthy people, the colour of their urine is a good indicator. The colour is meant to be straw-colored.

Take a peek while you're in the bathroom. That's the message.”Sounds easy, doesn't it? We need water, we consume it, and we must replenish it. But this is where things tend to fall apart. What is the basis for the 2.6-litre recommendation? Not, contrary to popular belief, a physiology analysis determining how much water the average person needs. Indeed, the guidelines provide no evidence that 2.6 litres is a healthy amount; 2.6 litres was chosen simply because it is the average amount consumed by most people.

When you think about it, this is a very strange idea. It's health advice focused on people doing what they've always done. Professor Collins claims that the recommendations urge Australians to "drink plenty of water" not because they are concerned about not drinking enough, but rather to encourage them to turn away from unhealthy sugary soft drinks. What about the other piece of water advice: eight cups of water a day? What's the source of that? It's difficult to say. Fredrick J. Stare, a well-known mid-century American nutritionist, appears to have been the first proponent. However, his guidance seems to be focused on personal opinion rather than experimental evidence.

The fact that there isn't enough evidence to say how much we can drink doesn't rule out the idea that we should be drinking more. Dehydration is a problem. Is it possible that many of us are dehydrated?

Since so much of the water we drink comes from food, we aren't aware of it. In addition, as a by-product of burning energy, the body produces about half a litre of water per day. Also debunked is the notion that coffee is a diuretic and does not count as water. Long-term dehydration has yet to be discovered in any population studies.