Alternate Names : Calories - Diet

Definition

The energy stored in food is measured in terms of "calories."

Technically, one calorie is the amount of energy required to raise the temperature of 1 gram of water 1 degree Centigrade (from 14.5 to 15.5). The "calorie" measure used commonly to discuss the energy content of food is actually a kilocalorie or 1000 real calories; this is the amount of energy required to raise one kilogram of water (about 2.2 pounds) one degree Centigrade.

Different foods can be used by the body to produce different amounts of energy -- which is why a small piece of chocolate can have many more calories than a similarly sized piece of lettuce.

However, since calories are a measure of energy, there cannot be, as some diet books claim, different "types" of calories. A fat calorie has the same amount of energy as a protein calorie by definition.