Re: How Much Can I lose
It is very unhealthy do practically starve your self (even for one week) to lose weight. You body will begin to slow your metabolism and actually burn muscle mass, rather than fat. When you start eating normally, your body will actually be worse off than before. It can cause you to have a harder time losing weight in the future (even when you are doing the same things that worked the past). It is good to watch what you eat and cut out junk food that will have a lot of empty calories. However, you need to make sure that your body is getting enough calories to perform it normal everyday functions.
A healthier way to lose the weight would be to eat fewer calories than you normally would, but not significantly more. Your body probably need at least 1700 calories to function daily. Also burn more calories by exercising. If you create a 1000 calorie defict a day (500 from eating less and 500 from working out), you should be able to lose about 1-2 a week. Losing much more than that is unhealthy and cause more problems down the road.
Maybe instead of losing weight, you should think about building muscle mass. Even if you don't want to get all bulky, doing some resistance training will make you look tone and the increased muscle mass will up your metabolism. With that and a little cardio and you should be able to lose whatever fat you are wanting to lose and will actually look and feel better.