Source: http://www.theatlantic.com/health/archiv...

Eating ice actually burns calories because it requires energy for the body to melt the cube. One curious doctor suggests this can be used as a legitimate weight-loss tool. 

When you eat a significant amount of ice, your body burns energy to melt it. Eating ice should, by the logic of this diet, also provide some level of satiety, if only so far as it physically fills space in the stomach and mouth.

By Weiner's calculations, ingesting one liter of ice would burn about 160 calories, which is the energy equivalent of running one mile. So you get to eat and burn calories. Ever since the death of upward mobility, that has been The American Dream.