Are you watching your calorie intake? For some, it has become a habit to scrutinize food labels and see the calorie count. Certain groups of people like athletes or sports enthusiasts training for a game, those who are losing weight , and those who are simply wishing to be fit and trim have calorie requirement or calorie intake limit for a day. The expression “I’m on diet, so I’m watching my calorie” has lend to the idea that diet and calorie becomes synonymous. Just what exactly is calorie?
Calorie is a pre-International System of Units (pre-SI) for energy. A calorie is a unit of heat required to raise the temperature of 1 gram of water by 1 degree centigrade at atmospheric pressure.1 The International System of Units (SI) for energy is Joules (J) but this measurement is often used in physical sciences. To express the equivalent of one calorie to joule:
- 1 cal = 4.184 J
In nutrition, Calorie (often with a capitalized C) also commonly referred to as food calorie or diet calorie is a unit of measurement to gauge the energy-giving potential in food. In this case however as with most food labels, calorie (cal) actually means kilocalorie (kcal) represented as:
- 1000 cal = I kcal
For example, a can of soda with 200 calories actually means 200,000 calories or 200 kilocalories of heat energy if subjected to complete combustion. A 100 gram Fried egg with 180 calories is equivalent to 180,000 calories or 180 kilocalories. A 100 gram whole milk has 70 calories which means 70,000 calories or 70 kilocalories of heat energy.
Is a Calorie Bad?
If calorie simply means heat energy, why do we concern so much with our intake of calorie? Anyway, our body needs energy. Of course we need energy to sustain our everyday activities; however, a surplus of calorie could result in mass gain. In other words, unused calorie is stored as fat. Naturally, nobody would like that. Agree? Here’s a sample illustration of how an extra calorie converts into gain weight,
- 7700 kcal surplus = I kg of gain weight
- 3500 kcal surplus = 0.454 kg of gain weight
Consider this with caution, however. Doctors and nutritionists consider this as a very simplistic estimate.2
How many calories do you need?
The recommended daily calorie intake for most of us is only 2000 – 2500 calories.
Remember, 2000 – 2500 is only a general recommendation on calorie intake. For athletes, or very active people and those with special needs – losing weight, recuperating from illness, undergoing health care management like diabetics, hypertensives – these groups may require a different calorie count. Calorie restriction using a recommended diet plan coupled with exercise may help improve mental function, heart health in overweight, hypertensive adults.3
Check this chart that serves as a guide to help you determine your calorie need considering your age, gender and activity level.
If you wish to personally know your own calorie requirements, you may use this calorie calculator, or consult your doctor or health care provider.
How the term Calorie came to be?
An article from the Journal of Nutrition (2006) published by the American Society for Nutrition entitled History of the Calorie in Nutrition authored by James L. Hargrove of the Department of Foods and Nutrition, University of Georgia, Athens explained that calorie was not actually a unit of heat in the original metric system. Before, modern kcal was used in 1852 by Fayre and Silberman or by Mayer in 1848, Nicholas Clement has already introduced calorie in his lectures on heat engines in 1819-1824 in Paris. The word calorie with its present definition entered the English language in 1863.4
Footnotes
- WordNetWeb. wordnetweb.princeton.eduhttp://wordnetweb.princeton.edu/perl/webwn?s=calorie
- http://whatis.techtarget.com/definition/0,,sid9_gci771826,00.html
- http://www.newsroom.heart.org/index.php?s=43&item=980
- http://jn.nutrition.org/cgi/content/abstract/136/12/2957