NLN PAX Science Practice Exam

Calories and kilocalories measure energy—the capacity to do work or produce heat. In nutrition, the energy in food is given in kilocalories, often called Calories with a capital C. One kilocalorie equals 1,000 small calories and about 4,184 joules. Temperature, on the other hand, is a measure of how hot or cold something is, not how much energy it contains or can deliver. Force describes a push or pull, and mass is the amount of matter in an object; neither of these quantities is what calories quantify. So calories and kilocalories are units of energy, used to express how much energy food can provide.