The past few decades have seen important changes in mensuration. Milliequivalents have replaced milligram percentages, and metric units of weight and volume have largely displaced traditional grains, drams, and ounces. Centimeters, of course, have completely taken over from inches. None of these changes received an immediate welcome, but physicians, pharmacologists, and biochemists have gradually learned to live with them and even to like them.
A new take-over is now threatening the science of nutrition and indirectly that of medicine. The calorie is about to become the most recent victim of metrication. Various national and international bodies, including the Comité Generale des Poids et Mesures, the International Organization for Standardization, the Royal Society, and the Bureau of Standards in the United States have all recommended the adoption of the joule as the unit of energy. As yet this recommendation has not received either the sanction or the disapproval of the medical
To Count Calories or to Juggle Joules?. JAMA. 1972;219(9):1206. doi:10.1001/jama.1972.03190350042012