The only way to lose fat is to consume less calories than you expend (or call a plastic surgeon)... problem is, when you calorie deplete, your body enters a catabolic state and you start to muscle-waste.
Anabolic-Androgenic Steroids keep your body in "building" (anabolic) mode... when you are anabolic, you will be "building" muscle - thus, using more calories towards muscle synthesis and raising your caloric needs. If you maintain your current caloric intake (your current diet) and take AAS, you will gain muscle mass and reduce % body fat. This would be hard to maintain though, in that you will be hungrier during cycles.
Cycles, doses, diets and routines are all goal-specific and user-specific... but at the end of the day - anything that keeps your body anabolic will allow you to diet without muscle wasting... and unless you are in starvation mode, you will be putting on muscle as well - the amount thereof, again, depends on diet and exercise routine.
As drrman said .. steroids arent magic. injecting and sitting on your ass with your increased appetite and gyno is going to get you nowhere fast ... when taking steroids, keep in mind the potential that you are / are not taking advantage of. Juice, eat right, work hard, sleep hard ;-) and you'll drop the spare tire...