Exercise. If you are thin, you will gain weight by exercising. People that are overweight will lose weight by exercising. Thing of it as the equalizing factor. It helps both under and overweight people get to a happy medium. Crunches on an exercise ball are the best. If you do standard situps, be sure not to put your hands behind your neck because this can put strain on your neck, try overlapping your hands on the base of your neck, and then support your head by squeezing your forearms together to hold you jaw in place.
Protein is an important factor in gaining muscle. Eating more protein and drinking protein shakes will help you build lean muscle without losing weight. It is also important to be consistant with the amount of weight you lift and the number of reps you do.
Losing weight overall is likely to affect your facial weight as well as your abdominal weight. However, to develop six-pack abs, you actually need to develop and strengthen your abdominal muscles such as by doing crunches and sit-ups. If you carry too much weight around your abdomen, no matter how toned your abdominal muscles are no one is going to be able to see them.
If the weight you are losing is muscle, yes.
It's difficult to determine whether you're losing fat or muscle without specific measurements. However, if you're losing weight gradually and maintaining a balanced diet with sufficient protein intake, you're more likely losing fat rather than muscle. Tracking your progress with body composition measurements can provide a clearer picture of your body changes.
No that is impossible. You cannot gain muscle mass without ever gaining weight.
move more and eat less
Reducing fat. You can lose weight with or without building muscle, by eating smaller portions and avoiding unhealthy foods. Though of course exercise is always a good idea whether or not it's for adding muscle.
Are you running enough? If not, I recommend you start running, that will help you loose weight.
Impossible, actually. Once you're anorexic you are going to keep losing weight, until you are the most anorexic you can be, and then you'll eventually die. Why would you want to be anorexic without losing weight? Isn't that the whole POINT of anorexia?
No. Mass is directly propotional to weight.
It depends if you get fat then go on a diet, or if you lift weights, you gain muscle,and muscle weighs more than fat.
You can be losing fat and gaining muscle at the same time, bringing your weight up. This is not necessarily bad at all. You may be getting quite a bit healthier losing the less dense fat and gaining healthy, toned muscle.