Drink up – it's good for you!

So what is that clear liquid in your glass? Water is a natural compound that consists of two parts hydrogen to one part oxygen. Water accounts for 60% of the human body; it's a vital part of us.

Drinking enough water is essential for good health, but many of us fall short. We should drink at least eight glasses of water each day – preferably spaced evenly throughout the day. Tea and coffee can count towards this, but bear in mind they are diuretics – in other words, they will encourage you to urinate, even if don't have enough water in your body. So watch those morning coffees! You've been sleeping all night without a drink, so what the body really needs is a glass of water – why not have one first, then a coffee afterwards?

We lose water every day, not just through going to the loo and sweating, but even breathing. Not getting enough water can cause tiredness, headaches, lack of concentration, constipation, an inability to absorb essential minerals and vitamins from food, and ultimately extreme dehydration, needing hospitalization and saline drips.

Drinking in hot weather and before and after exercise is a must, but it's equally important to remain hydrated in less obvious situations. For many of us, the first signs of needing water will translate as feeling hungry, so we'll often snack instead of drinking fluids. The afternoon slump when we feel a sugar craving is frequently caused by being thirsty. Avoid gulping water if you're feeling thirsty – sipping slowly will give the body a better chance of absorbing the fluid it needs. Watch out when drinking alcohol, which is another diuretic. If you are drinking, it's best to alternate alcoholic drinks with non-alcoholic ones. Hangovers are largely the result of dehydration.

An easy way to check whether you're sufficiently hydrated is to look at your urine colour. It should be very pale yellow (almost clear); the darker the yellow colour, the more you need water.

So next time you feel like reaching for something to eat, stop and consider whether or not what you really need is something to drink.