The Great Water Myth: 8 Glasses A Day Is For Fish

Everyone knows you're supposed to drink eight glasses of water a day. Many people also say that this water can only come from pure water, not milk, juice, soda, coffee, or tea. Some people even say that because caffeinated beverages actually dehydrate you, you need to drink an extra glass of water for each cup of coffee or can of soda.

Isn't it about time we all stopped believing this myth?

Water is very important, no question there. Composing about 75% of our bodies, it's truly the stuff life's made of, and we're constantly losing it through various bodily functions. Without water, we'll die in about three days. Yes, we need it, but who came up with these arbitrary rules about how much we need, and how we're allowed to get it?

First of all, why would it be exactly eight glasses a day for everyone, regardless of their size, level of activity, and weather conditions? It seems to me that a 500-pound man running a marathon on the equator would need more water than a baby girl sleeping at room temperature. But then again, I'm not a doctor.

Caffeine is a diuretic, meaning it causes you to lose water. But is it a powerful enough diuretic to not only completely negate the hydrating effect of the caffeinated beverage, but also dehydrate you so much that it takes a glass of water to catch up to where you were? This is pretty easy to test on your own. Wait until you're so thirsty you can't take it anymore, then drink ten sodas. Has your thirst been quenched, or do you need to be rushed to the emergency room? The consensus is that regular caffeine consumers lose little fluid, if any, from caffeinated beverages. And let's not forget they have caffeine-free soda. I believe that alcohol can dehydrate you, but if you're in the habit of drinking enough alcohol to be constantly dehydrated, you've got bigger problems than hydration anyway.

Do you drink as much water as the rules prescribe? Of course not. Do you feel chronically dehydrated, like your cells could give out at any moment? Of course not. Do you know why? Because there's water, water everywhere. Eat some grapes or an apple and tell me they're not gushing with water. Actually, most fruits and vegetables are more than 80% water. Even dry foods like cake, bread, and cheese are more than 20%. You get a fair amount of hydration just from the food you eat, let alone everything you drink other than water. It all counts, whether it's from pure water or not.

So let's stop obsessing over rules that were probably made up by Evian, and use common sense to decide when we need to drink. As it turns out, Sprite had the right idea: obey your thirst.