These functions include:
- Absorbing nutrients
- Regulating body temperature
- Transporting oxygen around the body
- Preventing constipation
- Making hormones and neurotransmitters
- Supporting cell growth and reproduction
- Flushing out waste products
- Lubricating joints
- Moistening your eyes, nose, and mouth
Although the amount of water you need to drink each day depends on the temperature outside, your activity levels and your body size, women generally need about 2.1 litres per day, and men need 2.5 litres per day. This is on top of fluids you get from the food you eat.
What's the best option?
As a rule, if you have access to potable tap water, then this is the cheapest and the most environmentally sustainable option. Using a glass or stainless-steel drinking vessel will reduce your exposure to plastic.
If you prefer the taste of filtered water, then this is a good option (even better if your filter is not made of plastic), although there is insufficient evidence of the health benefits of filtered water compared to tap water in Australia. Although it tastes fabulous and has the perfect number of bubbles, buying imported water from Italy and other places is not environmentally sustainable.