If you still can recall Physics in secondary school, a Calorie is a unit of energy. Scientifically, it is the amount of energy, or heat, taken to raise the temperature of 1 kilogram (kg) of water 1 degree Celcius (°C). So, when we drink ice water, our body has to heat up the temperate of the ice water to that of our body temperature. In other words, our body has to raise the temperature of the ice water, thus burning calories. If you have doubt, try to drink some ice water and then test the temperature of your urine. Does your urine feel cold or warm?
Now, let’s see how much calories can be burnt when we drink ice water:
- Assume the temperature of ice water at 0°C.
- Our body temperature is estimated at 37°C.
- A standard mug or glass holds approximately 250 millilitres (ml), or grams (g), of water.
- 250 g of water = 0.25 kg of water.
- It takes 1 Calorie to raise 1 kg of water 1°C.
Therefore, to raise 0.25 kg of the ice water from 0°C to 37°C, our body burns 0.25 x 37 = 9.25 Calories!
So, if we drink 8 glasses of ice water a day, which is equivalent to 8 glasses x 250 ml per glass = 2,000 ml = 2 litres = 2 kg of ice water, our body burns 2 x 37 = 74 Calories a day. This figure is actually not very impressive and significant, as it doesn’t even burn off the caloric intake of a tin can of Coca-Cola (143 Calories). Nevertheless, this small effort can contribute a little to enhance our daily caloric burning process. If one day we can burn 74 Calories extra, then that will be 518 Calories extra a week, and 2,220 Calories extra a month.
In a nutshell:
While we definitely shouldn't depend on ice water consumption alone to replace exercise or healthy diets, drinking cold water instead of warm water does burn extra Calories. Take it as an add-on process, not a whole process by itself.