How much water do you need to drink each day? What seems like a simple question doesn’t have a straightforward answer. While many experts recommend eight or more glasses a day, others contend you need to drink water only when thirsty.
In truth, how much water you need depends on your age, your health, how active you are, the weather and your diet. And depending on what you drink, you could be doing your body more harm than good.
Water is essential to your health. Water makes up roughly 60 percent of our body weight. It’s needed to regulate body temperature, transport oxygen and nutrients to cells, flush toxins from organs, keep your skin moist and cushion your joints.
Drinking enough water is also helps prevent kidney stones by flushing away chemicals that form stones in the kidneys.
Consequences of drinking too little – and too much – water
If your body loses too much fluid, you don’t drink enough water, or both, dehydration will follow. Infants and children are more vulnerable to dehydration than adults because of their small body weights and reduced sweat production.
The elderly are also at increased risk since they may be less aware of thirst or on medications that amplify the effects of dehydration.
Warning signs of dehydration include fatigue, loss of appetite, flushed skin, heat intolerance, light-headedness, dry mouth, and dark urine with a strong odour. But even mild dehydration can cause headaches, zap energy, decrease mental alertness and lead to constipation.
Under normal circumstances, most of us can trust our sense of thirst to prevent dehydration. Research shows that most people meet their hydration needs simply by drinking fluids with meals and when thirsty.
Drinking too much water can also be dangerous. Hyponatremia, or water intoxication, is a condition when blood sodium falls to an abnormally low level, prompting rapid swelling of the brain that can result in coma and death. Endurance athletes who drink large amounts of plain water in a short period of time are at greater risk.
How much water do you need?
Men should drink 3 litres (13 cups) of water each day and women need 2.2 litres (9 cups). Children, aged 1 to 3 years, need 1 litre (4 cups) daily and 4 to 8 years olds require 1.3 litres (5.5 cups). Teenagers need to drink more – about 1.8 litres (7 cups) for girls and 2.6 litres (10.5 cups) for boys.
These guidelines don’t apply to people who engage in moderate or vigorous exercise and they don’t account for hot weather, two factors that drive up the body’s need for water. Women who are pregnant need an additional 1 cup (250 ml) of water each day; breastfeeding women require an extra 4 cups (1 litre).
What counts as “water”?
This might sound like a lot of water, until you consider that everything you drink – excluding alcoholic beverages – counts towards your daily water requirements. Once you factor in coffee or tea, fruit juice at breakfast, milk on cereal, sports drinks, even soft drinks, you’re probably doing better than you think.
Use the following guide to hydrate without consuming excess calories, sodium, or additives.
Choose water first
our best choice is water – it’s free of calories, sugar, sodium, colouring and preservatives. If you don’t like plain water, add a slice of lemon, lime or orange to add flavour. Or add a splash of blueberry, pomegranate or cranberry juice to make water more interesting.
Consider carbonated water if you find still water boring. (Contrary to popular belief, Perrier water is essentially sodium free - only 2 milligrams per 250 ml serving.)
Keep a bottle filled with water and keep it with you – at your desk, at home, or in the car. Sip it slowly during the day; avoid gulping water quickly to prevent too many trips to the washroom.
Drink water during meals. Sipping on water between bites will increase your fluid intake and slow your eating pace. You might even find yourself eating less food before feeling full.
Get kids used to drinking water so they don’t become accustomed to drinking flavoured drinks all the time. Keep a pitcher of water on the dinner table.
Limit fruit juice
There’s nothing wrong with drinking a small glass of 100% pure fruit juice at breakfast to add vitamins and minerals to your meal. But if juice is your main source of water, you’re likely consuming more sugar – and calories – than you realize: 16 ounces (500 ml) of fruit juice supplies roughly 220 calories, 50 grams of sugar and only 1 gram of fibre.
Avoid sugary drinks
Aside from their hefty dose of refined sugar (9 teaspoons per 355 ml can), soft drinks also contain chemical additives to flavour and preserve. Colas – diet colas included – are made with phosphoric acid, an additive that can deplete calcium from bones if consumed in excess.
Other sugary drinks to reserve for a once in awhile treat include regular iced tea, lemonade, fruit punches, and vitamin waters. Glaceau ‘s VitaminWater, for example, serves up 8 teaspoons of sugar per 591 ml serving.
Sweet coffee drinks are dessert, not as something to quench your thirst. While Starbuck’s Frappuccinos and Tim Horton’s Iced Caps supply calcium-rich milk, they’re not easy on your waistline. A Grande Caramel Frappuccino contains 380 calories, 12 teaspoons of sugar and 9 grams of saturated fat.
Use sports drinks wisely
Sports drinks like Gatorade and PowerAde are intended to be used for exercise that lasts longer than one hour. They provide sodium to prevent hyponatremia in prolonged exercise. Most also contain liquid sugar and/or high fructose corn syrup to provide energy for working muscles.
Guzzling sports drinks outside of exercise will boost your intake of sugar and sodium. Prolonged consumption has also been linked to tooth erosion.
All research on this web site is the property of Leslie Beck Nutrition Consulting Inc. and is protected by copyright. Keep in mind that research on these matters continues daily and is subject to change. The information presented is not intended as a substitute for medical treatment. It is intended to provide ongoing support of your healthy lifestyle practices.