I think this is easier to see if we consider a milliter of water and stick with celsius.

1ml of water weights 1 gram, and raising this ml of water one degree celsius is 1 (little c) calorie.

Drinking 1 ml of ice water (at about 0 degrees celsius) and raising it to body temperature (at about 37 degrees celsius) thus takes about 37 (little c) calories.

Thus drinking a liter of ice cold water would consume about 37 (big C) Calories.

And a pound of fat contains 3500 Calories (kcal), so drinking about 100L of ice water would consume one pound of fat.

One could drink 15L per day (about one liter per hour and 5x the recommended minimum intake) and burn about one pound of fat per week.

Or just sit in an ice bath. Also, I wonder if the reverse is true: if you drink a warm drink does that cause calories that would have been burned heating you to not be burned?

Plus the energy to melt the ice, 0.016kg * 334kJ/kg = 5334J = 1274 cal.

A grand total of 1.8kcal per ice cube. Only 1000 ice cubes and you could eat twice as much as usual!

At around 16 liters of water once melted that would be an interesting Darwin Award for sure.

So 0.5 dietary calories? You're better off doing one jumping jack.

So your math is right (I think), but the calories in food are kilocals (capital C Calories). So it's .5 Cal /cubic inch.

Your body is already at body temperature, and it’s at least 1000x the mass of the water, so the amount of energy required to move it to body temp is tiny, relatively speaking

> at least 1000x the mass of the water

Minor nitpick but: Typical glass of water weights 250g, but typical (even obese) human weight is very far from 250kg :) Guess you put one too many zero.

But they were talking about an ice cube, not a glass of water

You're right that that's significantly more than just a few, but it's still actual calories, not food calories.

Or in metric - weight of the ice in grams, multiplied by difference in temperature of your body and the ice.