Fat Fast

I can’t seem to get rid of this last amount of fat around the bottom of my stomach, so I’m sporting a little 4 pack. I’ve been using md6 and t2 with a lower carb diet and I just can’t shake it, so I was thinking about fat fast, but I don’t really want to loose any strength etc. so whats the minimal time you can be on this diet to see results or can you do something like mon-fri fat fast with the weekend to eat solid food and repeat?