Quite a few people have been asking me lately just how much water they are supposed to be drinking when trying to lose weight. Should they be drinking less, more, or the same amount as usual? Is it really possible to speed up weight loss by simply drinking less?
Want rapid weight loss? Simple, drink less water!
The other day I went on a 12 km hike that took me about two hours. It was in the middle of a hot summer day and I was walking uphill. Well at least the first half of the hike, on my way back I was walking downhill. I didn't bring any water, which was a kind of a foolish thing to do, since the hike turned out to last nearly twice as much as I originally planned. And besides that, the heat also took me by surprise. It just so happened that I weighed myself just before the hike, so I took the opportunity and weighed myself again immediately after the hike. And the results were astonishing. I lost a whooping 2.2 pounds (1.5kg) in a manner of two hours!
But before anyone starts running up the hills in the middle of a summer without any fluids, let me just come right out and say that drinking or not drinking water can't boost weight loss! It's actually quite the opposite. If you fail to drink enough water, your body becomes dehydrated and this causes your metabolism to slow down. This means you will be burning fewer calories than usual and you can also expect your energy levels to drop. Regardless of whether you are trying to lose weight or not, it should be in your best interest to stay properly hydrated at all times.
Sure, you can lose weight by not drinking water and/or accelerating sweating (which I inadvertently did on my hike), but this is not the weight loss you should be going for. During the hike I burned approximately 750 calories, which means I actually lost less than 100 grams of body fat and everything else was simply water weight. In a previous post of mine I already explained why you should focus on losing ONLY your body fat when trying to lose weight.
How much water do we need?
Different studies suggest different daily amounts of water, but the general consensus seems to be at about 3 liters (about 13 cups) for men and 2.2 liters (about 9 cups) for women. However, this is a general recommendation and there are many other factors that can influence your daily water needs like temperature, activity levels, special health conditions, etc. You also need to bear in mind that water can be ingested in many different forms not only by drinking it directly. You will also be working towards meeting your daily water needs by drinking various juices (or most other drinks for that matter) or eating watery fruits and vegetables. Even the seemingly "dry" foods can still contain a surprising amount of water.
After my hike, I owed my body about 1.5 liters (about 6 cups) of water. But instead of drinking water, I ate one half of a watermelon. I am a huge fan of watermelons, especially when it's hot and I'm really thirsty and/or exhausted. I don't even bother cutting them into pieces I just cut them in half and eat them with a spoon. This particular half of watermelon weighed about 5.5 pounds (2.5 kilograms) without rind. And let me tell you that the word watermelon starts with "water" for a reason. By ingesting this much watermelon I also ingested about 2.2 liters (about 4 cups) of water.
This means I was able to more than recover all of the water (and calories) lost during the hike without actually drinking anything. Unfortunately this also meant that I more than recovered my pre-hike body weight. But this didn't matter, the real victory was losing close to 100 grams of body fat on that hike.
Regardless of whether or not you are trying to lose weight, you should always keep your body properly hydrated. Water weight loss does not equal body fat loss, which is the only thing that should really matter in any weight loss attempt. I don't care if you drink or eat your water, just make sure you get enough of it or you might actually be putting the brakes on for your metabolism.