I doctor the food up a lot. I've been at it since April, and still have 50 pounds to go, so I decided from the beginning that I would do whatever I could to stick with the plan.
I add salsa to the chili, cocoa powder or instant coffee to shakes, vanilla to pancakes and brownies. I just had a pancake muffin - nuke the pancake mix in a mug sprayed with Pam, add vanilla, splenda, cinnamon & fake butter spray to the mix.
If you don't use any of the optional condiments, you will probably lose weight a little faster than if you did. But for me, I need to keep the food interesting so I stay on the plan.
Do whatever works for you, and good luck!
Lost the first 100 with Medifast, now working on the last 25