You are most definitly not going to burn much fat, if any in 3 days. It may add a negligible amount. All the weight that is going to be lost is water, and glycogen stores. When I cut, I go very low carb during the week, and then Saturday, I allow myself to drink, Sunday I can eat whatever I want. I gain 7-10lbs on a sat/sun, and lose it all after a couple days back on the diet. This bet is ridic simple.