What is a calorie?
(Lansing State Journal, May 8, 1996)


This question brings up the topic of how scientists measure energy.  Energy can take many forms.  One form energy can take is heat.

The calorie is a unit used to measure heat.  It is defined as the amount of heat needed to raise the temperature of 1 gram of water by 1 degree Celsius.  If you want to raise the temperature of 10 grams of water by  degree Celsius, it would need 10 calories of energy; to raise the temperature of 10 grams of water by 10 degrees Celsius, would likewise cost you 100 calories.

The calorie is often associated with food and dieting.  Dietitians have measured the amount of energy that foods contain.  If the body performs work (converting some of the stored potential energy into kinetic energy) and uses more energy than it consumes as food, the body will deplete its store of energy.  Because a lot of the body’s stored energy is in the form of fat cells, a lifestyle that consumes more energy than it takes in can reduce the amount of fat in one’s body.

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