It has been suggested that by drinking a gallon of cold water a day, you can burn an extra 150 calories.
Such statements provoke my inner skeptic so here’s the math… (sorry folks but this calls for metric).
Q: Will drinking a gallon of water burn burn 150 calories?
A: energy required = mass * change in temperature * specific heat capacity
- 1 gallon of water = 3.785 kilograms
- Cold water temp = 5C (estimate of course)
- Body temp = 37C
- Specific heat capacity for Water = 1 Kcal per kilogram
Therefore: 3.785 * (37-5) * 1 Kcal = 121 Kcal
OK close but no cigar.
To burn 150 Kcal, the starting temperature of the water needs to be… -2.6C!
Yikes! That’s a block of ice.
But perhaps they are also adding in all the legwork back and forth to the toilet.