The amount of heat required at a pressure of one atmosphere to raise the temperature of one gram of water one degree Celsius that is equal to about 4.19 joules.
Got it? Me neither!
So, if you would like to know how many calories a day you should consume, here's a chart that simplifies it. Take a look at the chart. If you want to lose about one pound per week, reduce your caloric intake by about 500 calories.