Calorie

It is generally used in publications and package labels to express the energy value of foods in per serving or per weight, recommended dietary caloric intake,[6][7] metabolic rates, etc.

[6][7][8] In physics and chemistry, the word calorie and its symbol usually refer to the small unit, the large one being called kilocalorie (kcal).

[2] This usage was adopted by Wilbur Olin Atwater, a professor at Wesleyan University, in 1887, in an influential article on the energy content of food.

In 1928, there were already serious complaints about the possible confusion arising from the two main definitions of the calorie and whether the notion of using the capital letter to distinguish them was sound.

[16] The joule was the officially adopted SI unit of energy at the ninth General Conference on Weights and Measures in 1948.

Until 1948, the latter was defined as 4.1833 international joules; the current standard of 4.184 J was chosen to have the new thermochemical calorie represent the same quantity of energy as before.

[26] In the European Union, on nutrition facts labels, energy is expressed in both kilojoules and kilocalories, abbreviated as "kJ" and "kcal" respectively.

Dieting is the practice of eating food in a regulated way to decrease, maintain, or increase body weight, or to prevent and treat diseases such as diabetes and obesity.

As weight loss depends on reducing caloric intake, different kinds of calorie-reduced diets have been shown to be generally effective.

[citation needed] The lingering use in chemistry is largely because the energy released by a reaction in aqueous solution, expressed in kilocalories per mole of reagent, is numerically close to the concentration of the reagent in moles per liter multiplied by the change in the temperature of the solution in kelvins or degrees Celsius.