I get asked about water intake relatively frequently. The answer to this question though isn’t really a one size fits all.
First I want to mention that water acts as a catalyst in a number of intracellular metabolic reactions that might otherwise not be possible if water was not present. Basically this means that you need adequate water intake for fat burning reactions to take place.
So how much should you be drinking? People of different sizes will need to consume different amounts of water. An easy calculation is having 30-40 milliliters of water per kg of bodyweight. So for example, if you weigh 65kg you would need 1.9 to 2.6 liters of water.
However, there are a lot of other factors that can effect how much water you should consume including caffeine intake (caffeine is a diuretic), how much you sweat during exercise, and what kind of climate you live in. I usually like to recommend between 3 and 4 liters per day for active people but again, this can vary based on your size.
A good way to determine if you are properly hydrated is to listen to your body. Pay attention to the color of urine and if you feel thirsty. If urine is very light in color, almost clear, then you are well hydrated and should keep drinking at the same rate. You can use the chart below as a guide. If your urine is darker than what is on the chart, you may be severely dehydrated and at a health risk. I would like to note that I am NOT a doctor but I think we can all agree that urine should not be dark brown.