The normal process of Ketosis (fat burning) often goes in 2-3 day cycles. This is becasue as your body utilizes the fat stored in your cells for energy it oftens waits to then consume the cell and the tissue surrounding the cell. Your body will then fill that now "empty" cell with water till it has time to fully absorb the cell itself. This whole process can take between 2-3 days and can result in sudden 1-3lbs of weight lost overnight as the body flushes the water out and finishes the fat burning process.
However, if you have gone 4 full days with no weight loss at all you may want to consider doing an "Apple Day".
This is a method used in the phase 2 reduction phase to help break a plateau:
For one full day, abstain from all foods with the exception of the following:
- 6 large apples of any variety
- Water to maintain hydration
Return to the normal routine the next day and Viola your back on track losing weight. Keep in mind you probably would have seen the weight loss anyway but the Apple Day can be more helpfull for your state of mind and your motivation.