As a dietitian, I talk about nutrients all day long, but one nutrient is often overlooked in people’s diets. They want to be meticulous about grams of protein or fiber, but they forget about the most important nutrient of all: water! Water makes up more than two-thirds of our body. It’s used to regulate temperature, lubricate joints, aide in metabolism, keep your eyes moist, and so much more.
How much is enough?
We’ve all heard about eight glasses of water a day. This can be a good measure for some people, but just like how everyone doesn't need the same amount of protein, everyone doesn’t need the same amount of water. When estimating water needs in a clinical setting, I base water needs on body weight using this:
(kg body weight – 20) x 15 + 1500 = ml fluid requirement
This can be a great base, but you may still need more if you’re working out and sweating, live in a hot climate, or don’t eat lot of fresh produce. Instead of counting milliliters, I just like to use cues to see if I’m on track for my hydration. First, I pay attention to urine color. This may not be the most glamorous test, but it works. Drink enough so your urine is pale yellow, like a glass of lemonade. Also, if your urine has an odor, that can also be a sign of dehydration, so if it smells strong, drink up.
A couple of ways to make sure you get enough water is to carry a water bottle with you and drink throughout the day. Drink water when you wake up, before and with meals, and anytime in between. Hunger can often be confused for dehydration, so it’s a good idea to drink before snacking. Also, because your food provides about 20 percent of your total water intake, make sure to take advantage by filling up on water-loaded fruits and vegetables. Some of my favorites are watermelons, strawberries, spinach, and broccoli. They’ll not only help you hydrate, but because of their high water content, they’ll also help you feel full on less calories.
One time that you’ll want to really combat dehydration is during exercise. Because dehydration can lead to muscle fatigue, loss of coordination, decreased energy, decreased performance, and heat exhaustion or stroke, you definitely want to be well-hydrated when you’re exercising. Weigh yourself before and after exercise to get a good idea of your hydration status. You’ll want to drink enough water to keep your weight the same. Even small changes like 1–2% body weight can start to have negative impacts on performance, and greater than 3% can lead to heat stroke.
To prevent this, drink water throughout the day and have at least eight ounces right before exercise. After exercise, aim to replace your fluids within two hours. If you remembered to weigh before and after, drink 20–24 fluid ounces of water or a sports beverage for every one pound lost.
Be careful not to overdo it. Even with water, you can drink too much. Over-hydration can be dangerous, due to an electrolyte imbalance in the body. This is a condition called hyponatremia. This typically occurs when you’re drinking and sweating a lot. If this is the case, be sure to replenish your electrolytes, as well as water, with a sports drink. Also, don’t drink more than one liter or quart per hour during exercise.
So if you want to improve your health, start with water. Skip the soda, juice, and energy drinks and get enough water! It’s essential for life, and getting enough is essential to living a healthy active life. So, drink up!
Megan Ostler MS, RDN
iFit Dietitian
WARNING: This post is not intended to replace the advice of a medical professional. The above information should not be used to diagnose, treat, or prevent any disease or medical condition. Please consult your doctor before making any changes to your diet, sleep methods, daily activity, or fitness routine. iFit assumes no responsibility for any personal injury or damage sustained by any recommendations, opinions, or advice given in this article.
