and which kind of household exercises will tone arms?
I sure can. Well remember that carbohydrates esp white ones are pretty empty in calories. Whole wheat is better. It also depends on how much pizza youre eating as well as if you are exercising or not. Remember that weight gain is equal to putting in more calories than you are burning. Usually you can find online the pizza youre eating and see how many calories it is per slice. Then you can do some cardio and burn that slice or slices right off based on the calories.
The key to looking lean and showing stomach muscles is cardio, cardio cardio! I suggest doing intervals instead of slow steady cardio. This way your body is burning more calories to the change in pace. So you can achieve more results in a shorter period of time. (LESS BORING TOO). So that means whatever type of cardio you choose pick time intervals to go hard then ease off, then hard again for at least 20mins-60minutes. You will see a leaner stomach faster this way. Also when you are sitting around at work, or school, driving etc practice tightening your stomach muscles on and off so youre constantly working those abdominal muscles and preventing weight gain.