Few know origin of calorie

Julius Robert MayerATHENS, Ga., Nov. 20 (UPI) -- Many try to forget about calories on Thanksgiving; others are obsessed with counting them, but a U.S. expert says few know why food is measured in calories.

"We all teach this unit, (the calorie) and nobody knows where it came from, not even the historians of nutrition," said James L. Hargrove, associate professor of foods and nutrition in the University of Georgia's College of Family and Consumer Science.

Formally, a calorie is a measure of the amount of energy required to heat 1 kilogram of water 1 degree Celsius. It was first used in engineering and physics, but eventually found its niche in nutrition, where it is used to measure the amount of energy food contains, according to Hargrove.

Hargrove credits German physician Julius Mayer for beginning a dialogue about food as an energy source. Before Mayer's time, Hargrove said people thought energy was God-given; they made no concrete connections between the food they ate and the energy on which their bodies ran.

A popular early nutrition text published in 1918 by Lulu Hunt Peters outlined 100-calorie portions of many foodstuffs and preached counting calories as a way to regulate weight, explains Hargrove.

source - UPI