Mayo Clinic states that it takes approximately 3500 calories to burn one pound of fat. In order to lose weight, a person must burn 3500 calories per each pound of fat they wish to lose.
To lose weight, a person must reduce the number of calories he eats per day. It is also helpful to exercise in order to burn extra calories. If a person simply reduces their caloric intake by 500 calories per day through diet and exercise, then they should be able to lose one pound of fat per week; this is because 500 multiplied by seven equals 3500 calories.