“Drink eight 8-ounce glasses of water a day,” the advice goes. If you read up on how to lose weight, that’s one of the first recommendations you see. But what is the mechanism behind a robust water intake and weight loss?
There are several factors at work.
For one thing, being sufficiently hydrated allows your body to perform at its highest level. You have more energy, so you feel more like being active instead of sitting around lethargically watching TV.
Another aspect is that having enough water in your body helps flush out waste products created through exercise and weight loss. When you are even slightly dehydrated you simply don't recover as quickly as when you are well-hydrated.
When you don't recover as fast, you might get in 3-4 workouts a week versus 5-6 when you recover quickly. More workouts more often equal a better chance of losing weight.
The third mechanism involves your kidneys and your liver. Normally, your kidney’s job is to filter out waste products to produce urine. When you don't drink enough water (and most Americans don't), they can’t do their job right.
And when your kidneys can’t do their job right, they need help, so your liver steps in and takes in some of the filtering work. The problem is that your liver’s primary role is to metabolize fat…and now it can’t do that.
As a result, you don't burn stored fat, and fat that you consume in your diet is stored instead of burned.
In order to free up your liver so that it can devote itself full-time to burning fat, you need to drink water, and lots of it. This will allow your kidneys to function normally.
How much water is enough? It varies widely according to:
- Your bodyweight—heavier people need more water than thinner people.
- Your level of activity—if you’re exercising to the point of sweating (as you should be), you are losing water at a rapid rate. don't wait until you’re done to hydrate.
- The ambient temperature—even if you’re just sitting outside, you will need more water in the summer when it’s hot. And in winter, you may need more water if you overdress and sweat under your clothing.
- Your metabolic rate—some people sweat easily and profusely, others less.
The best guideline is to drink half your bodyweight in ounces of water per day. The best way to tell if you’re properly hydrated is to check the color of your urine. If it is clear at least once per day, you’re drinking enough water.
However, if it is yellow, you are somewhat dehydrated. Dark yellow means very dehydrated. Conversely, if it is clear, you can ease off on water consumption for the next hour or two.
Gerry Morton, CEO of EnergyFirst, has these recommendations for working more water into your daily routine:
- Always carry a water bottle with you, just like you do your wallet or purse.
- When your bottle goes empty, refill it or purchase another one.
- When working out in the heat of summer, or doing outdoor work, drink 20 ounces of water every hour, broken down into 6 ounces every 20 minutes.
- Drink a full glass of water (8-12 ounces) first thing in the morning when you get up, and do the same right before you go to bed.
- When you’re tempted to reach for a soda or a drink, have a glass of sparkling water instead.
- If you drink alcohol, alternate each drink with a glass of water—alcohol is very dehydrating and you need to refill your “tank.”
More reasons to drink water.