Lose 2 pounds of fat, you have to burn about 7000 calories.
It is said that 1 lbs of fat equal to 3500 calories, lose 2 lbs is 3.5K*2=7k cals, lose 10 lbs is 3.5K*10=35k cals…
So if you want to lose 2 lbs a week, that is a total 7000 calories during a week, 1000 calories a day.
And it is said that a grown person need about 1500 – 2500 calorie intake a day, this depends, your height, weight, age, sex, physical activity…
But you had better never eat less than 1200 calories, because eating too little food makes you body enter into a starvation mode, you body will think that food is scarce, and store more calories as fat. So, starve yourself sometimes do not have any effect on your weight loss.
Say your daily calorie intake is 2500 now, and what your body need is 2200, you should decrease 300 calories, and do workout to burn more 1000 calories. So, what you need to do is cut out the excess calorie intake, and exercise to burm more calories to lose the accumulated fat.
For how many calories you need a day, visit
http://en.wikipedia.org/wiki/Basal_metabolic_rate
http://health.discovery.com/tools/calculators/basal/basal.html
http://www.caloriesperhour.com/tutorial_need.php