How Much WATER Should You DRINK A Day? Harvard Trained Doctor

I cannot emphasize how important water is for your gut health and overall wellness. So in this video, we are going to talk about how much water you need. How do you know whether you are dehydrated? What water actually does to you? And how water actually gets inside your cells? Let's dive deep into it. Hey everyone, I'm Dr. Sethi. I'm a gastroenterologist and I help you optimize your gut health. If you like this content, don't forget to hit the subscribe button. Water consumption is a key for our health because each and every cell of our body needs water. The more important thing is whether the water is getting inside the cells or not. The temperature of the water does not make a big difference in this case. Whether you drink cold water, warm water or hot water, it doesn't matter. The transfer of water into the cells happens regardless. Except the fact that warm or hot water can increase bowel motility and make you poop better. Overall, if you like cold water, drink cold water. If you like warm water, it's okay to drink warm water. It doesn't matter that much. Whatever the temperature, the water will still transition inside the cells. So what happens after the water gets inside the cells? The water has to combine with the proteins. All our activities like walking, talking, our basic metabolic rate, everything is dependent upon the proteins inside these cells. And for the proteins to function properly, the water has to combine with these proteins inside the cells properly. Inside the cells, they form stable bonds like an electric factory with positive and negative charges binding together. This bond stability is essential for cells to function properly. And from these cells, the hormones are secreted, including your insulin. If the cell is not working properly, your insulin does not work properly. And then the food that you ate is not going to be digested properly. So it is all linked together. The key thing is that the cell has to work properly. And for that cell to work properly, the water has to bind to these electrons and protons so that they are forming stable bonds. When the negative charges are more, we call these as free radicals. And these free radicals are the main reason for damaging the cell membrane. If the cell membrane is damaged, the cell is damaged, which means the hormones are damaged and you're not going to get the maximum outcome of the hormone that you were supposed to get. This can lead to endocrine problems like hypothyroidism, adrenal problem, obesity, and diabetes. So how does water help? Water acts as an antioxidant, which means when water gets into the cells, it covers all these negatively charged electrons so that they don't damage the cell membrane. So water in this regard is an antioxidant. So the next question is how much water you should take. So there are a lot of factors that go into an exact equation to determine how much water you need. Like what is your hydration status, what you are doing currently, whether you are exercising, whether you are in a hot and humid climate. But in general, if I have to summarize and if I have to give you a bare minimum value to target, it would be that in the first 10 hours of waking up, try to consume 240 ml or 8 oz of water every hour up to 10 hours from the time that you wake up. This is approximately 2.5 liters of water in the first 10 hours of you being awake. In my clinical practice, I've seen that most of my patients do not even reach this minimal fluid requirement on a daily basis. A very common misconception is that we should be drinking water only when we are thirsty. This is the biggest mistake. Thirst is not a good indicator for your hydration status. And you ask why this 10 hours? The science behind this is fascinating. It is all about the sleep-wake cycle for each and every organ in our body, including our heart, intestines, and even kidneys. Just like how we sleep at night and wake up in the morning, kidneys also wake up in the morning and work continuously doing their filtration for 10 hours. During this filtration process, you need to supplement kidneys with a lot of water so that the entire body is filled with hydrating fluids and it is maintained in a good homeostasis. On a cellular level, this is what is happening. When you actually look into the kidney cells under a microscope, the filtration process goes down significantly after 10 hours of you waking up. For example, if you woke up at 7 am, you drank 240 ml of water every hour until 10 hours, you're done with your 2.5 liters of water, you could actually see the active filtrative process for the first 10 hours. And then beyond the 10 hours, that is after 5 pm, the activity of the kidney cells goes down significantly. So one of the questions I get asked very commonly is, when you drink 2.5 liters of water per day, you're going to wake up in the middle of the night to use the restroom more frequently. To avoid this, you need to make sure that you get your 2.5 liters of water in the first 10 hours of you waking up. Once you do that, then your body is adequately hydrated, you don't have the urge to go to the bathroom because most of the filtration process is done within the first 10 hours of you waking up. Second, we know that activity in the kidney cells goes down after 10 hours of you waking up. For example, if you woke up at 7 am, then after 5 pm, the activity of your kidneys filtrative process goes down, which means you should try to avoid drinking more than 150 ml or 5 ounces of water after 10 hours of waking up, which is usually around 5 pm for most of us. And number three, which is very important and very fascinating as well, the urge to go to the bathroom at night is directly proportional to whether you're gulping the water or you are sipping the water. If you gulp the water, the water goes inside the bladder and it stretches the mechanical receptors of the bladder. Imagine that a bladder is like a balloon and it expands. When it expands, it touches the nerve supply and that sends a signal to the brain. And even though you're sleeping, it will wake you up and urge you to go to the restroom. So if you want to avoid waking up in the middle of the night to use the restroom, please sip the water after 5 pm and not gulp it. In the first 10 hours of you waking up, it doesn't matter whether you gulp or sip because your filtrative process in the kidney is very active. So when I say two and a half liters, it does not have to be just plain water. It could be freshly squeezed juices or it could be any other liquid, but not coffee. Coffee, as we know, is a diuretic, which means that it excretes water from the body, not to an extent that you will be significantly dehydrated, but it really makes a significant impact. Multiple research studies have shown that even 2% of dehydration will make us lose focus. Because coffee is a diuretic, you need to drink water two times more than the amount of coffee that you drank. I love coffee for its taste and also for the myriad of health benefits that it provides us. You don't have to stop coffee. Just make sure that whatever amount of coffee you're drinking, you need to drink water double the amount of that coffee and add it on top of your daily water intake. For example, if you drank 250 ml of coffee, you need to supplement yourself with 500 ml of water on top of your normal requirement. So this equation of approximately two and a half liters of fluids in the first 10 hours after you wake up will be determined also by the fact whether you are exercising, whether you are in a hot and humid climate, and also your age and any diseases like kidneys or heart problems. The water intake should be higher if you routinely exercise or you live in a hot and humid climate. So how do you test whether you are dehydrated during a particular day? A simple test is a skin pinch test. When you pinch the skin at the back of your hand, if it gets flattened within one to two seconds and goes back to its original position, this means that you are well hydrated. But if it takes more than five seconds to return, that means you're likely dehydrated. It is important to note that this is just a rough test and skin elasticity and age also play a significant role in this. You could also check your urine color and make sure it is not dark yellow. This color would mean you should drink more until your urine turns either clear or light yellow. So that's all for today guys. If you think this was valuable, make sure to hit the subscribe button and I'll see you in the next video.