Of all the things you can do to help you lose weight, consuming mass quantities of water is probably the most important. It doesn’t matter whether you drink sparkling or still, bottled or tap, mineral or filtered, as long as you’re getting copious amounts of good ol’ H₂O, you’re on the rocket train to Hydrationtown.

You never know what other benefits drinking water could provide. Maybe someone will want to trade the “good package” for a simple glass of water.

Our bodies are comprised of about 60% water, so it’s no wonder we need an intake of fluid in order to function properly. The average person can survive a week to ten days without food. Without water you wouldn’t survive more than 2–3 days, tops.

We’re not interested in mere survival and standard body functions, though. How does water help you lost weight?

Ways That Water Helps You Lose Weight

• Tastes Great. More Filling – Water fills you up. If you drink a big glass of water before eating you’ll eat less because you’re full of water. It sounds stupid, but it’s effective. Water, which has no calories, displaces other things that contain calories.
• Reduces Water Retention – This one’s counter-intuitive, but if you’re not properly hydrated your body will retain as much fluid as it can so all of your systems can function properly. Drinking more water actually makes you retain less water. Easing water retention by pumping plenty of water through your system means you won’t be weighing that excess water when you step on the scale. Reducing the amount of water you retain is the cheapest and easiest way to lose body weight.
• Stops You From Confusing Hunger With Thirst – Your body can’t really tell the difference between being hungry and being thirsty. If you keep your stomach full of water for most of the day, you won’t feel as hungry as fast.
• Gets Your Body Moving – Researchers have discovered that drinking a lot of water helps to increase sympathetic nervous system activity and constricts blood vessels, which prevents pooling of blood throughout your extremities.
• Increases Your Metabolism – Drink water, burn more calories (slightly). Some will tell you that drinking really cold water will burn calories just warming it up, but really it’s not that hydration increases your metabolic rate as much as when you’re dehydrated your body slows it down in order to conserve water. By hydrating properly you’re making sure that your metabolism runs at a full clip as often as possible.
• Lubricates Your Joints – Water helps your muscles contract and lubricates your joints (which is why athletes that don’t properly hydrate get muscle cramps). The last thing you need when you’re trying to add more exercise to your life is to have cramps from not drinking enough fluid.
• Displaces Caloric Beverages – If you’re drinking as much water as possible, that means you’re probably replacing some caloric beverage with water, which in and of itself could save you a large number of calories depending on your drinking habits. Calories from alcoholic and sugary drinks (about 7 calories per gram of sugar or alcohol) add-up very quickly. Having said that, all non-alcoholic water-based beverages hydrate you, just none as much as pure water.
• Helps Your Kidneys Take Out The Trash – I read quite a few articles (that I won’t link to) that said something to the effect of “drinking water helps flush impurities and toxins out of your body.” The problem with this mumbo-jumbo is that it’s sorta true, from a certain point of view. Your kidneys are like your body’s filtration system, and are responsible for producing urine and for depositing waste into it, so if you drink more water you’ll keep the crap from staying in your body and get it into your urine faster. If you’re interested in how your kidneys work, How Stuff Works has a pretty good explanation.

Urination: Your New Hobby

Let’s get this out of the way – if you drink a lot of water you’ll have to pee a lot. Think of this newfound activity as a hobby and use your bathroom breaks as a good excuse to get up and move around every hour or so.

Your urine should be mostly clear in color (except for the first pee of the day which may be cloudier). An easy test for how hydrated you are is to look at the color of your urine.

So having to pee a lot is annoying, especially when you’re out and about and have to rely on public restrooms. When at home or at work, though, at least drinking more fluids will get you moving a little between getting up to refill your water glass or getting up to go use the restroom.

How Much Water To Drink

The conventional amount suggested is eight 8oz glasses of water per day. The truth is that the amount of water you need varies per individual, amount of activity, how much you sweat, how hot it is outside, how much you exercise, your altitude, and all sorts of other things you can’t easily measure. Heck, you lose 1–2 liters per day, which is half of your daily water loss, just through breathing[1]. So we can’t really go strictly by volume.

The Mayo Clinic recommends drinking 2.2 to 3 liters per day, which is close to the minimum 1.9 liters (8 x 8oz) various health organizations suggest.

Another rule of thumb is to drink half your weight in pounds in ounces of water. So if you weigh 150 lbs., to drink at least 75oz of water per day (which is more than 8 glasses). That seems high to me, but again it really depends on the person. Maybe you need that much water. Maybe you don’t. So how much water should you drink?

You should drink as much water as you can. Drink so that you urinate frequently (once an hour or so is probably the right amount) and that your pee is clear instead of yellow (your first urination of the day may be darker). If you’re drinking a lot of water, peeing a lot, and your pee is clear, you’re probably getting enough water.

Food generally attributes about 20% of your fluid intake as well, as many foods contain water, so you’ll also get some hydration simply by eating, but not nearly as much as by drinking water.

How Much Is Too Much?

It is actually possible to drink too much water, although it’s really difficult to do so. When you drink too much water the electrolytes (salt and other minerals) in your blood gets diluted and your kidneys can’t process the water fast enough. You develop a condition known as “hyponatremia,” the most severe symptom of “water intoxication” caused by the overconsumption of water.

However, it’s not just the sheer amount of water that is a problem, but rather how fast you drink it. The kidneys of a healthy adult can process about 15 liters of water throughout the course of the day. If your kidneys process water linearly (and they don’t – they actually work harder while you sleep than while you’re awake) that means they can process about half a liter per hour, outside of what your stomach and the rest of your body holds. So you’re going to be hard-pressed to overdo your water intake unless you try to drink several liters at once.

As with anything, it’s better to regulate your intake and have a steady and constant amount of fluid going through you rather than trying to get it all in at one time.

For people with healthy kidneys the most common side-effect of drinking too much water is more frequent urination.

Diuretics

A diuretic, like coffee/caffeine or alcohol is considered to make you urinate more frequently and to dehydrate your body. That’s true, if you consume vast quantities of coffee or other caffeinated beverages. In practical use, though, you’ll get more hydration from the water in coffee than the diuretic effect of the caffeine can remove.

Alcohol is a different story, not because there isn’t water in a lot of alcoholic beverages (in beer and wine more than hard liquor), but because alcohol affects the kidneys and increases your rate of urination. For every 1g of alcohol drunk, urine excretion increases by 10ml[2] (for the duration that alcohol is in your bloodstream, which is a complicated matter that depends on numerous factors[3]).

Let’s put that into perspective. An “alcohol unit” is a standard measure for what constitutes a single alcoholic drink. In the U.S. one alcohol unit is about 10ml or 8g of pure alcohol (while a pint of water may weigh a pound, alcohol is a little lighter than water). A pint of beer is about 568ml. For our purposes we’ll say that our pint of beer is a standard lager containing about 5% alcohol by volume for a drink that’s around 200 calories. That means that there’s 22.4g of alcohol, which means that your urine excretion rises 224ml per hour.

Keep in mind that the diuretic effect of alcohol doesn’t just expel extra water from the alcoholic beverage you’ve consumed, but any water in your system. You can see why alcohol is said to dehydrate you.

Sparkling or Still?

You should drink water more than any other beverage, but carbon dioxide (CO₂) contains zero calories, so if you like fizzy water, get a Sodastream or buy Seltzer.

Beware store-bought soda that isn’t flavored, though, as these are not all the same:

• Seltzer – Just water with CO₂ bubbles dissolved in it. 0 calories / cup.
• Club Soda – Seltzer water with bicarbonate of soda (baking soda) dissolved in it. Usually 0 calories, but often a lot of sodium is added as well. Some brands will use the terms seltzer and club soda interchangeably.
• Tonic Water – Seltzer that has quinine added to it for flavor. It’ll protect you from malaria, and if you shine a blacklight on a bottle it’ll glow even though the concentration of quinine is very low. Actually, many cheap supermarket brands don’t even contain quinine anymore, instead opting for another chemical that has a similar flavor. Most tonic water also contains sugar or high-fructose corn syrup. For example, a 12 oz can of Canada Dry Tonic Water contains 140 calories, almost as much as a can of Coca-Cola (which has 160 calories per can).

Drink water or seltzer water. Drink the other two in limited quantities, and know that it’s not a health drink when you do. When in doubt, check the label or better yet, make your own seltzer.

Bottled or Tap?

Either one will help you stay hydrated, but is bottled water worth the additional cost over plain ol’ municipal tap water?

Before we contrast and compare, consider that nearly half of all bottled water is actually sourced from local tap water.

There are some major disadvantages to drinking bottled versus tap water:

Cost

At an average cost of $3.79/gallon, bottled water is about 1,900 times more expensive than tap water, even when bought in bulk. Smaller single-serving bottles can be as much as five thousand times more expensive. At the airport or movie theater, twice that.

So the next time you buy a bottle of water, consider if its convenience makes it 5,000–10,000 times better than tap.

For what it’s worth, I buy bottles of water all the time when we’re out and about and prefer simple filtered tap water like Aquafina or Dasani (bottled by Pepsi Co. and Coca-Cola respectively). Sometimes it’s just not convenient to carry your own refillable water bottle. When I do buy bottled water, though, I know I’m being overcharged for it, and resent it. You’re on my list, Regal Cinemas.

Quality

Municipal water quality varies from location to location, whereas bottled water quality tends to differ only by brand.

The Environmental Working Group (EWG) did an enormous study a few years ago to determine the quality of various brands of bottled water, and published a scorecard on a scale of A-F, as in school. A few brands received a grade of B or C, but the majority received Ds and Fs.

The study’s conclusion was that while for the most part bottled water quality was on-par with municipal tap water, it was rarely, if ever, better.

Bottled water is often just filtered tap water, but filtering removes many of the valuable minerals in the water. One essential mineral that is missing from most bottled water is fluoride, which is added to most municipal water sources to prevent tooth decay. Of course, most toothpaste also contains fluoride.

Safety

Bottled water is regulated by the FDA whereas tap water is regulated by the EPA. The FDA is also responsible for inspecting bottled water plants, although according to the FDA web site:

FDA monitors and inspects bottled water products and processing plants under its general food safety program, not a specific bottled water program. Because FDA’s experience over the years has shown that bottled water has a good safety record, bottled water plants generally are assigned low priority for inspection.

The Natural Resources Defense Council (NRDC) performed a study in 1999 to determine the quality of more than a thousand bottles of 103 brands of bottled water and found:

While most of the tested waters were found to be of high quality, some brands were contaminated: about one-third of the waters tested contained levels of contamination – including synthetic organic chemicals, bacteria, and arsenic – in at least one sample that exceeded allowable limits under either state or bottled water industry standards or guidelines.

The afore-linked-to EWG study on bottled water quality also lists several safety concerns:

Laboratory tests conducted for EWG at one of the country’s leading water quality laboratories found that 10 popular brands of bottled water, purchased from grocery stores and other retailers in 9 states and the District of Columbia, contained 38 chemical pollutants altogether, with an average of 8 contaminants in each brand. More than one-third of the chemicals found are not regulated in bottled water.

The types of chemical pollutants found were quite varied:

Altogether, the analyses conducted by the University of Iowa Hygienic Laboratory of these 10 brands of bottled water revealed a wide range of pollutants, including not only disinfection byproducts, but also common urban wastewater pollutants like caffeine and pharmaceuticals (Tylenol); heavy metals and minerals including arsenic and radioactive isotopes; fertilizer residue (nitrate and ammonia); and a broad range of other, tentatively identified industrial chemicals used as solvents, plasticizers, viscosity decreasing agents, and propellants.

Drink up!

Environmental Impact

There’s an environmental cost to getting water to people no matter whether it flows through pipes or is bottled and shipped on a truck, but consider the added environmental costs of bottled water over tap:

• The bottles have to be manufactured.
• The bottles are manufactured from petroleum (usually).
• Many states don’t offer a return on five-cent deposit on water bottles like they do for beer and soda.
• Because there’s no deposit, a lot of water bottles end up in landfills.
• Even those bottles that do get recycled have costs associated with recycling the plastic.
• Bottled water is often sold far from where it’s bottled, meaning that it has to be shipped on trucks, barges, etc. throughout the world. Consider also that water is heavy[4].
• Local communities often get shafted by large water-bottling corporations who take their ground or spring water without repaying the community.

Considering that nearly half of the bottled water sold is tap water anyway… why not drink the stuff that’s better regulated, safer, and cheaper?