Do you ever get to the afternoon and feel tired, with a headache and the best way you can describe how you are feeling is “blah”?
You think back over the day and realise the only water you’ve had was in your morning coffee – six hours ago!
This is not an uncommon situation; we get busy and something as simple as having a glass of water gets put to the back of our minds.
What makes it worse is that the feeling of “thirst” is in response to being dehydrated, which means that we only start feeling thirsty when we are already dehydrated.
What does water actually do?
Water is the most vital nutrient in your body – you can last weeks without food, but only days without water.
This is because our body is made up of on average 60% water (depending on your amount of lean body mass), and forms part of almost everything in your body. It is involved in all metabolic processes in your body and is necessary for digestion, transport, absorption, excretion of waste, thermoregulation and dissolving of nutrients.
How much water should I be drinking?
It is recommended that everyone aims for 2 litres of water a day however, there isn’t a one size fits all approach.
The amount of water you should be consuming is dependent on a number of things, including temperature, amount of exercise you’re doing, your lean body mass and your diet. Because of this, you will never have the same requirements as someone else, and even your own requirements will change from day to day.
The National Reference Values suggest that men should be having 2.6L and women 2.1L of fluids which includes water as well as milk, tea, coffee and other drinks. So 2 litres of water is a good rule of thumb; as long as you reach this, you will be well on your way to reaching your daily requirement.
What happens if I don’t drink enough water?
Have you ever been for a blood test when you are dehydrated? I have. Normally my blood tests are over nice and quick, but this time it took twice as long as it normally does. My blood was thick – the phlebotomist (and yep, that’s a real profession) told me it was like trying to suck mud out of my veins. Because your blood is made primarily of water, if you start getting dehydrated you begin to lose water from your blood so it concentrates and becomes thicker.
During hotter weather, we normally need more water because we are losing more through sweat to help keep us cool. Dehydration in hot situations like this can cause heat exhaustion, loss of consciousness and heat stroke. Losing just 2% of your body weight in water can result in impaired physiological responses and reduced physical and mental performance – and 2% is just 1500ml (1.5L) for an average 80kg man.
Is it possible to drink too much water?
Yes and no.
Too much water causes hyponatremia which is very dangerous. This is a condition where the amount of sodium in your blood is too low. Sodium helps maintain fluid balance in your body and it is also vital for nerves and muscles to work properly. When you drink too much water, you end up diluting your blood which causes low sodium. That is the “yes” part – technically, it is possible to drink too much.
The “no” part is that hyponatremia as a result of excess water consumption is very rare and would require you to drink enormous amounts of water in a very short period of time. There are rare cases of this actually occurring, an example was a 28 year old woman who competed in a radio show competition. She drank 6 litres of water in 3 hours and passed away not long after due to hyponatremia. A healthy kidney is able to excrete around 0.8 – 1L of water every hour, so theoretically a person could safely consume around 3 litres in 3 hours without experiencing any changes to the sodium concentration.
What are some benefits of drinking enough water?
Besides keeping you alive, drinking water has heaps of benefits for your everyday life. Here are a few:
- Weight maintenance: this occurs in a couple of ways. The first is simply replacing sugary caloric drinks like soft drink and juice. This is a simple switch that can have a huge effect on your overall calorie intake which will help with weight loss. The other way is by “preloading” with water. This is when you have a big glass of water before a meal to modify your body’s perception of feeling full. Studies have shown that preloading with 500ml of water 30 minutes before meals, led to moderate weight loss compared to those who didn’t preload.
- Bowel health: Having enough fibre is vital to maintaining regular healthy bowels. One of the functions of fibre is to absorb water and make the stool easier to pass. However, if you are having enough fibre but not enough water, it can actually make things worse. So having adequate water ensures that things pass through easily keeping your bowel healthy.
- Detoxes: I’m sure you have heard of all the wondrous detoxes you can do, from lemon water to charcoal. All claim to rid your body of the toxins that are making you unhealthy. But the best detox is actually water. The primary role of our liver and kidney is to remove toxins, and the water we drink flushes through our body taking with it all the nasty toxins removed by our organs.
- Improves alertness and concentration: Dehydration can cause disruptions in mood and aspects of cognitive functioning including concentration, alertness and short term memory.
To take home: It is encouraged that you aim to drink at least 2 litres of water and other fluids each day. As long as you’re not drinking any more than 1L per hour, you are not at risk of drinking too much.
Finally, the amount of water your body needs will depend on heaps of different things but the main ones are the temperature and the amount of exercise you do, so if it’s hot and you’re exercising, make sure you drink extra.
Author: Ashleigh Hamilton, BHlthSc (Nutr & Diet), MSc (Diet), APD.
Accredited Practicing Dietitian and Nutritionist, Ashleigh Hamilton, is passionate about a whole of body approach to health which encompasses both physical and mental aspects. She works with people to make lifestyle changes that will benefit their health for the future, using a range of counselling techniques including aspects of cognitive behavioural therapy, mindfulness and person-centred therapy.
To make an appointment with Brisbane Dietitian and Nutritionist, Ashleigh Hamilton, try Online Booking – Mt Gravatt or call Vision Psychology (Mt Gravatt) on (07) 3088 5422.
- Parretti, Helen M., et al. “Efficacy of water preloading before main meals as a strategy for weight loss in primary care patients with obesity: RCT.” Obesity 23.9 (2015): 1785-1791.
- Popkin, Barry M., Kristen E. D’Anci, and Irwin H. Rosenberg. “Water, hydration, and health.” Nutrition reviews 68.8 (2010): 439-458.