I have always worked under the principle of if you reduce your weights and increase your reps while your body is in its most catabolic state you are bound to lose size, keep with the as near to the same weight as you were lifting before, 8 reps for most exercises, stimulating as many muscle fibres as possible but cut the sets.
Its all about maintaining muscle size/mass whilst dieting and yes its then all about the style, quantity and quality of food you eat. I find moderate pace early morning cardio helps and so do caffeine tablets when i am feeling low.
Hope this helps
btw i have just had my bodyfat tested after 10 weeks of dieting and its 8.2% one week to go late 7's is the target.