It works because the body is forced to sue fat as fuel instead of carbs, but you do feel like shit, from what i've heard. Im starting my cutting cycle this week
me at 145lbs last october:

Me right now at 160lbs after bulk cycle
bicep shot

double bicep(bad posing ):
Im trying to cut back to 150 at 9% body fat like the 145 pic, Im thinking of going low carb for 4 weeks but its hard because most food contains a shitload of carbs, also i need to get a thermogenic pill to raise metabolism.