What is a Calorie?

[KAL-uh-ree]

Food energy is the amount of energy in food that is available through digestion. The values for food energy are expressed in kilocalories (kcal) and kilojoules (kJ). Commonly a kilocalorie is simply referred to as a "Calorie". In other words, nobody really discusses a Kilocalorie when discussing food energy; rather, people mention a Calorie and they are really referring to a Kilocalorie.
Technically speaking, one food Calorie (1 kcal or 1,000 calories) is the amount of digestively available food energy (heat) that will raise the temperature of one kilogram of water one degree Celsius.

Calorie name coined by Atwater in 1895
http://en.wikipedia.org/w/index.php?title=Food_energy&oldid=206923896

How many Calories do I need per day?
Use the "Grocery Genie" Calorie Calculator!

This adult daily calories calculator gives an approximation of your basal metabolic rate - the number of calories per day your body burns.

If your goal is to lose weight by burning off excess body fat, aim to eat simply fewer calories per day than your daily caloric needs, and maintain or increase your exercise activity.

Calories Per Day Calculator for Adults

Enter into the calculator your Gender, Height, Weight, Age and Activity Level in order to calculate the number of calories you need to eat each day in order to maintain your weight.

Female	Male
Your height:	4 5 6 7 feet 0 1 2 3 4 5 6 7 8 9 10 11 inches
Your weight:	pounds
Your age:	years
Activity level:	Sedentary Lightly Active Moderately Active Very Active Extremely Active
To maintain your weight you'll need: calories per day
Note: these calculations are based on averages. Athletes or people recovering from illness may require a higher caloric intake to maintain their current weight. Speak to your trusted health professional for personal advice.