Key Difference – Calories vs Energy
In order to survive and do our day to day work, we need to obtain energy in various ways. Usually, all the animals obtain energy from their diet, and they oxidize their food to obtain energy. In a biological system, the energy is described in terms of Calories. Therefore, thekey difference between calories and energy is that Calorieis a unit of energy. In this article, Calories, energy, and the difference between are described in more detail.
What is Calorie?
卡路里isa unit used to measure the amount of energy在特定的食物中。卡路里表示的能量等于将1 ml水的温度升高一个度摄氏度所需的能量。Nutritionistsusually talk about large amounts of calories, and hence, it is more useful to considerkilocalories. However, in food science, kilocalorie is also called a Calorie abbreviating as ‘kcal’ or ‘Cal’.
The caloric energy of a particular food can be measured bybomb calorimeterin which the amount of heat released is measured and recorded by incineration of the food. The caloric value of a food varies with the number and type of chemical bonds between atoms. For example, one gram ofsucrosecontains 4 Calories, but one gram ofglucose包含3.7卡路里。Enzymesandcoenzymes(biochemical catalysts) are responsible for the conversion of Calories into fuel that can be used by cells.
What is Energy?
There are no better definitions for energy, but simply itcan be defined as the capacity to do work. According to thelaws of thermodynamics, there are some basic principles we should consider when talking about energy. One is that the energy cannot be created or destroyed, but it can be converted from one form to another. Animals gain energy byoxidizingthe food they eat. Plants, however, can independently produce their own energy byphotosynthesis.
Energy is in various forms, such askinetic energy, potential energy,thermal or heat energy, electrical energy, chemical energy, etc. Usually, energy is measured inkilojoules. However, the energy in biological systems is often measured in terms of Calories (4.184 kilojoules = 1 Calorie).
What is the difference between Calories and Energy?
Definition of Calories and Energy
卡路里:卡路里是营养学家用来测量特定食物能量量的一种能量单位。
Energy:Energy is the capacity to perform a work by utilizing the physical or chemical resource.
Unit of Measurement
卡路里:In biological systems, energy is measured in Calories, which isabbreviated as ‘kcal’ or ‘Cal.’
Energy:Usually, energy is measured in kilojoules, which is abbreviated as ‘kJ.’
Conversion – kJ to kcal
4.184 kilojoules = 1 Calorie or kcal
Image Courtesy:
1. "Oxygen Bomb Calorimeter" by Fz2012 (Own work) [CC BY-SA 3.0或者GFDL]， 通过Wikimedia Commons
Why do nutritionists confuse the issue by using “calories” if they mean “kilo-calories”? How do we know which is which when they’re both written “cal” or “calorie” Even in this piece, we encounter, “…one gram of sucrose contains 4 Calories…”. is that real calories? Or because you’re talking nutrition, it’s kilo-calories?
I’d be in favor of decertifying any “nutritionist” who doesn’t use the term “kilo-calorie” when they mean “1000 calories”.