How much water do we need to drink every day? If someone tells you a number, run. There is no number because the real answer is, “It depends”. It depends on several different things, none of them are how much coffee you drink.

It depends on the weather outside. You need more to drink when it is hot and humid than you do when it is cold and dry. The more you perspire (and from here on out I’m calling it sweat), the more you need to drink.

It depends on what you are doing or have recently done. If you are sitting on the patio reading a good book you need less water than if you are at the gym working like a maniac. Again, the more you sweat, the more you need to drink.

It depends on what you eat or have eaten. If you have a bowl of deliciously covered in melted butter and salt popcorn you need to drink more than if you a bowl of deliciously chilled watermelon.

Your body strives for homeostasis. It’s what drives most of your autonomic nervous system. You need to maintain your body’s pH and you never even think about it. You need to maintain your oxygen level and you only think about when you get short of breath. You need to do many things to keep yourself alive and your body only lets you know about when there is danger ahead.

If you don’t breathe, you will die in a matter of minutes. If you don’t eat, you will die in a matter of months. If you don’t drink, you will die in just a matter of days. It is the second most important thing your body needs. Air, then water, then food, and at a far distant remove are all the other things.

So, you body lets you know when you need air and you breathe. Gasping for breath is a terrifying thing and we try to avoid it, but some of those workouts are just that difficult. When your body is getting low on water, you get thirsty.

Food is trickier. We now live in a time of unnatural abundance. Food was never this plentiful and most of one’s life was making sure there was enough of it to get through the winters or lean times. That’s why we store fat, just in case we run out of food later. We don’t just get rid of the extra calories we don’t need right now like we do with water. And now that food is abundant, we eat often when we aren’t hungry.

Having noticed this early in the last century, some diet people advocated that you drink more calorie free water in order to fill your stomach and your time. This should stop you from eating out of boredom. And so the eight-eight rule was born out of dieting, not anything medical.

I am a Baby Boomer. Back when I was in school, there were no water bottles in every child’s hand. We got to line up and get a drink at the drinking fountain before or after morning recess, at lunch, and on very hot days – again in the afternoon. Otherwise we just turned into sand dunes. Wait, we didn’t. We all lived to become this massive economic wave still irritating all those after us.

That’s because you don’t die of thirst in a matter of minutes and being thirsty will eventually get you to a water source, at least in this country where we have plumbing and water fountains spread around like dandelions in spring. You don’t have any bad consequences from not drinking all damn day long even when you aren’t thirsty.

In fact, one of the problems with this nonsense is when you drink too much after dinner. Then you are up half the night getting rid of all that excess water you didn’t need in the first place when what you really do need is a good night’s sleep. Americans are woefully under-rested. There are very important physiological and psychological things that take place while you are sleeping. And when you are up making trip after trip to the bathroom, they don’t get done. By the way, your kidneys know you need to sleep and slow down their filtration during the night so you can sleep. All this extra drinking is thwarting your body’s real health system.

I was nurse for over twenty years. Never once in all that time did we ever force any patient to drink a certain amount of water. We did, on occasion, have to limit the amount of water patients got. If you have certain medical conditions, your body will not get rid of the excess fluid and it builds up in your lungs and you can drown.

I have no idea if all this drinking to excess and for no good reason is going to cause any medical issues down the road. All of the United States is being used as a test to see if overworking kidneys for no reason whatsoever will lead to kidney failure later in life.

People in countries without good plumbing are not drinking half their body weight in water and an extra cup of water for every cup of coffee and throwing some in for good measure just in case. They don’t die of dehydration although they might die from lack of cleanliness which would be exacerbated by using water to drink when not thirsty instead of cleaning up bacteria laden messes.

Every time I see someone telling me how much water I have to drink, I know they know nothing about health, science, or medicine. They are spreading an old wives’ tale based on a dieting tip that may or may not have any basis even in dieting.

If you are thirsty, get a drink. If you aren’t, enjoy your life. And get a good night’s sleep because that is really important.