If you are not an advanced bodybuilder, Dianabol is GREAT for losing FAT while cutting. Losing WEIGHT is another story but irrelevant in this case.
If you are seeking to preserve or even BUILD muscle mass while cutting, a low to moderate dosage of Dianabol is perfect.
For more advanced bodybuilders like myself however, a greater androgenic component is necessitated and thus a small dosage of testosterone should always be included in your cutting cycle.