When MealPlanMagic is "thinking" you may see a message in the bottom right corner of Excel: "Calculating: X%" that will give you an indication that things are being processed.  You may find this happening most frequently when you are customizing your Food List.  Just be patient and don't click around until it's finished.  The speed at which is processes is dependant on how many other applications you have running and the speed of your computer.

One trick that may help is going to the Formulas ribbon and turn Calculation Options to Manual.  Once you're finished entering information, we recommend turning it back to Automatic or hitting "Calculate Now" (shortcut: F9 key).  Generally speaking, like most spreadsheets, MealPlanMagic will run more smoothly on computers with more processors or that are running 64-bit Excel.