# Homework Help: Are calories actually burned?

1. Apr 13, 2006

### Raza

What really is a calorie?
Are calories actually burned?
Why is this terminology used?
What are the relationship among a calorie to measure food energy, a calorie to measure heat?

Last edited: Apr 13, 2006
2. Apr 13, 2006

### DaveC426913

A calorie is a unit of energy. 1 calorie of energy will raise 1 gram of water 1 degree C.

Calories aren't burned, but chemical processes usually involve oxidation, which is a slow burn, which is what is measured by the calorie.

The food calorie is actually a KCal. (the amount of energy to raise 1 kg of water by 1 degree) i.e. 1 food calorie is equivalent to 1000 calories.

These days, in the science world (though not in the nutrition world) the calorie is deprecated. The Joule is more common usage. 1 calorie is 4.185 Joules.

Last edited: Apr 13, 2006
3. Apr 13, 2006

### Mattara

According to Google calculator 1 calorie = 1/0.239005736 Joule which would make it closer to 4.184 (4,18400000...) Joules.

4. Apr 13, 2006

### Astronuc

Staff Emeritus
Getting nitpicky ( ) -

- http://physics.nist.gov/Pubs/SP811/footnotes.html#f11

http://physics.nist.gov/Pubs/SP811/appenB9.html#HEAT - conversions for units of heat (energy)