If you want to lose weight you need to know something about calories. You know that some foods have more than others. Fattening foods have more calories. Diet foods have fewer calories. But what are calories, really, and what do they have to do with you losing weight and keeping it off?

Calories are basically a measurement of heat. For example, if you are going to boil water you have to heat it. The amount of heat it takes is measured in calories.

A scientist will tell you that it takes one calorie to raise the temperature of one gram of water by one degree. (These are calories with a small