Appears in

Oxford Companion to Food

Oxford Companion to Food

By Alan Davidson

Published 2014

  • About

Calories units for the measurement of energy, including energy obtained from food. In the eyes of scientists the unit is now obsolete, but the word is part of everyday language, at least in English, and shows no sign of falling into disuse.

Strictly, a calorie is the amount of heat required to raise the temperature of 1 gram of water by 1 °C. This is a very small amount, and dietitians found it more convenient to use the kilocalorie (kcal), 1,000 calories, in their calculations. Unfortunately they called this a ‘Calorie’ with a capital C. The use of the capital was often misunderstood or omitted, causing much confusion. In popular usage 1 kcal is ‘a calorie’.