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Individual Needs


The human body is about 55% to 75% water.  About 83% of blood, 73% of muscle, 25% of body fat, and 22% of bones is water.   Drinking water and other fluids helps to:

  • control body temperature, heart rate, and blood pressure
  • remove waste
  • transport nutrients through the body
  • lubricate joints
  • facilitate digestion
  • keep skin nourished and firm
  • reduce risk of kidney stones
  • maintain energy levels

There is also some research that shows drinking water may help to suppress appetite in weight-loss efforts.  But how much should we drink and what beverages are best?

Individual hydration needs vary from day to day.  There is no scientific evidence to support the claim that we should all drink 8 glasses of water per day.  On average, adults need about 2 – 3 litres or 9 – 12 cups of fluid each day.

The goal of hydration is to ensure maintenance of body systems.  Being just 2% dehydrated can affect mental functioning and athletic performance.  Dehydration can also lead to higher blood glucose levels, as the glucose in blood becomes more concentrated when there is less fluid present. That’s why it’s important to drink and stay hydrated before signs of dehydration appear.  

An adult loses about 10 cups of water per day through breathing, sweating, and urinating. This amount is usually easily replaced through regular eating and drinking. However, long periods of time without drinking can lead to fatigue, headache, and other symptoms of mild dehydration.


Signs of Dehydration

  • dry, sticky mouth
  • sleepiness or tiredness
  • thirst
  • dry skin
  • decreased urine output, and dark urine

  • headache
  • dizziness or lightheadedness
  • muscle cramping
  • nausea
  • chills
  • constipation

What to Drink?

Water is the best choice, as it is a zero-calorie thirst quencher. But you don’t have to guzzle water to stay hydrated. To help meet hydration needs eat your water in vegetables, fruit, and other foods, and drink other beverages including tea, coffee, and milk.

Hydration for Activity

Increase fluids when active, especially when temperature is a factor. To determine how much you need, weigh yourself before and again after your activity. Drink enough during and after activity so that your body weight before and after is the same.

If you want to become more active, speak to your doctor to ensure you do so safely. Exercise can blunt thirst, so remember to take sips of fluid frequently when physically active.

Too Much of a Good Thing

Too much water can be a problem. Low sodium levels (hyponatremia) is a life-threatening condition that occurs when athletes drink too much water while doing prolonged high intensity exercise. This dilutes the body’s sodium levels without replacing lost electrolytes. Hyponatremia is usually seen in endurance athletes, such as marathoners and triathletes, but can also be experienced by non-athletes, especially those taking care to reduce the sodium in their diet.

Signs of Hyponatremia (water intoxication)

Signs of Hyponatremia

  • weight/fluid gain
  • mental confusion
  • general weakness

Can lead to:

  • seizure
  • coma
  • death

Tips for staying hydrated

  • Eat your water. All foods contain some water that contributes to hydration e.g. an orange is 90% water.  Moisture in foods accounts for about 20% of the average person’s total daily water intake.
  • Drink water at work. A busy work schedule is no excuse to ignore signs of thirst. Sip fluids regularly to help stay mentally sharp all day.
  • Add Flavour. We’re more likely to drink something that tastes good! If you don’t like the taste of plain water a simple fix is to add a low-calorie beverage flavour or a vegetable or fruit wedge e.g. lemon, lime, orange, or cucumber. 
  • Enjoy coffee or tea.  Contrary to popular belief, these caffeine-containing beverages are not dehydrating. While caffeine is a mild diuretic, the effects are outweighed by the amount of water in a cup of coffee or tea. 
  • Avoid alcohol .  Alcohol is more dehydrating than other beverages, and can lead to low blood glucose up to 24 hours after consumption! If you’re taking diabetes medication get advice from your doctor to ensure safety. Always drink responsibly – the Canadian Diabetes Association recommends no more than 2 drinks per day for men and 1 drink per day for women.

Water is the most essential nutrient for the body.  Keep your body happy by giving it the fluid it needs every day. 

The content of this article is for information purposes only. The content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health care provider with any questions you may have regarding a medical condition.