How Much Water Should Your Really Be Drinking?
We all know that water accounts for about 70% of the body. However, are we all drinking enough to replace the fluids we lose on a daily basis? The general consensus for water intake is around 8 glasses per day. Does this really take into account age, sex, weight, height or even how big the glass is? As with most things, water intake should not be generalised but rather dependant on the individual.
What Does Water Intake Affect?
Research supports the claim that your energy levels and brain function suffer due to dehydration. A study in 2012 showed that degraded mood, finding tasks harder, lower concentration and headaches resulted from mild (1.36%) dehydration in young females. Other studies support this conclusion as mild dehydration caused by exercise or heat can harm various other aspects of brain function. Physical performance can also be negatively affected by mild dehydration, leading to reduced endurance. Although 1% of body weight does not seem that bad, it is incredibly significant and usually happens when you are sweating a lot.
Studies suggest that increased water intake can reduce body weight by decreasing your appetite and increasing your metabolism. Two studies have shown that drinking ½ a litre of water can temporarily boost the metabolism by 24-30%. It was estimated that drinking 2 litres if water per day increased the energy expenditure by about 96 calories per day. Drinking cold water could lead to more calories being used as it takes more energy to heat the water to our own body temperature. You can also reduce the number of calories consumed by drinking water about 30mins prior meals, this is seen in older people more so. Another study showed that individuals on diets who drank ½ a litre of water prior to each meal lost 44% more weight than the controls, over 12 weeks.
4 Health-Related Complications That Respond Well To An Increased Intake In Water:
Acne and skin hydration: Although there have been no studies to confirm this, there have been anecdotal reports on how water can reduce acne and help hydrate the skin.
Cancer: Some studies have shown that an increase in water intake can lead to lower risk of bladder and colorectal cancer, although it is important to note that other research has not had similar results.
Kidney stones: The risk of kidney stones may be reduced by an increase in water intake
Constipation: Although constipation is a common problem, increasing water intake is a simple yet effective way to help.
How Much Should You Actually Be Drinking?
Whilst the European Food Safety Authority (EFSA) proposes the following guidelines, each individual is different and requires food and hydration according to their body.
If you really think about it, an All Blacks player should not be drinking the same as a jockey. Whilst they could both be adult men, their body anthropometry, weight and age could be completely different. A simple rule of thumb would be do drink 40ml of water for every kg of body weight.
In Essence
Water intake affects more than we think. There is no Golden Rule for daily water intake. You need to find what works best for you. Aim to drink 40ml for every kg of body weight and adjust it to your needs. Carry around a drink bottle so you can refill and keep track of how much water you are drinking daily. This works to avoid dehydration and overhydration. Drink more when you start sweating and include electrolytes to replenish the salts you lose whilst sweating.
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