60% of our bodies might be made up of water, but does that really mean we need to drink at least 8 glasses of it a day? What happens to your body if you don’t drink the right amount? Will your organs shrivel up and die from dehydration? Where did the magic number of “8 glasses” a day come from anyway?
Here’s the truth
We definitely do need to drink water every day, but the exact amount we need varies, depending on your body size, physical activity levels, climate, and the type of food you eat.
The 8-glasses-a-day rule dates back to 1945, and may stem from a misinterpretation – they forgot to add that part of your daily water intake comes from food. In fact, there’s no scientific evidence to suggest that you need to drink more water than what your thirst dictates. Our kidneys work to perfectly balance and regulate our water requirements so that we take in and retain as much fluid as we need.
There are exceptions though
Certain diseases like diabetes can alter your thirst mechanism, and elderly people often have a poorly-regulated thirst mechanism. There are also some situations in which you’ll want to drink a bit more: hot, humid weather causes you to lose more water through sweating, and if you’re sick with a fever or vomiting you’ll lose liquid that way too. Pregnant and breastfeeding women also need to drink more water, as do athletes and people who exercise every day.
The bottom line is; drinking 8 glasses of water a day is certainly a healthy habit, but if you follow your thirst, you won’t go wrong. Remember, pre-modern man never ran around sipping on a water bottle. A dry mouth indicated it was time to run to the stream for a drink, but you get to use a tap!